nuc Coupler knuckle By www.freepatentsonline.com Published On :: Tue, 16 Dec 2014 08:00:00 EST An improved coupler-knuckle assembly is comprised of a coupler body, a knuckle, and at least two knuckle retainer plugs. The knuckle has an internal coring geometry that increases the cross-sectional area of the throat portion of the knuckle compared to previous designs. The present invention's knuckle design includes a top and a bottom tapered holes in the knuckle with a locking groove at the bottom of each tapered hole for the knuckle retainer plugs to snap into. The knuckle retainer plugs are inserted through the coupler body and into the tapered holes in the knuckle. The improved coupler-knuckle assembly of the present invention reduces fatigue on the coupler, knuckle, and knuckle pin, prevents misalignment of the coupler-knuckle assembly, and prevents knuckle pin breakage. Full Article
nuc Connection device for a system for filling jars for the production of nuclear fuel By www.freepatentsonline.com Published On :: Tue, 21 Apr 2015 08:00:00 EDT A system for filling a jar with powdery material, for example for the manufacture of nuclear fuel, including a device for connection between the jar and a material feed system, where the device includes: a stationary connection portion connected to the feed system,a connection portion which moves relative to the stationary connection portion intended to be connected to the container's filling orifice, where the moving connection portion includes in the area of a downstream end a lip seal to achieve a tight connection by contact with the contours of the jar's filling orifice and where the said downstream end is connected to the stationary connection portion by a bellows so as to provide mechanical disengagement between the downstream end of the moving connection portion and the stationary connection portion. Full Article
nuc Method for filtration of harmful gas effluents from a nuclear power plant By www.freepatentsonline.com Published On :: Tue, 05 May 2015 08:00:00 EDT A method for filtration of harmful gas effluents from a nuclear power plant including the steps of providing a gas effluent from a nuclear power plant, the effluent including a mixture of gases; filtering the harmful, notably radioactive elements from the gas effluent by membrane separation through at least one membrane, the membrane separation being achieved by sifting, sorption and/or diffusion; storing the filtered harmful elements in storage reservoirs, and discharging the processed gas effluent to the atmosphere. Full Article
nuc Dressing device for a grinding wheel and its use in a centreless nuclear fuel pellet grinder By www.freepatentsonline.com Published On :: Tue, 05 May 2015 08:00:00 EDT The invention relates to a device for dressing a grinding wheel, comprising a sleeve to hold a corundum rod laterally and to guide it along its longitudinal axis, a ram to apply constant thrust force onto the corundum rod held in place and guided in the sleeve, to bring it into contact with the grinding wheel, means of rigidly connecting the ram shaft to the end of the corundum rod, and linear guide means for the sleeve for translating the corundum rod parallel to the axis of the grinding wheel while keeping the rod pressed against the grinding wheel with a constant force. Application to a centerless grinder in which the grinding wheel is used to grind nuclear fuel pellets. Full Article
nuc Apparatus for removing heavy polynuclear aromatic compounds from a hydroprocessed stream By www.freepatentsonline.com Published On :: Tue, 07 Oct 2014 08:00:00 EDT An improved apparatus strips HPNA's from hydroprocessed streams in a fractionation column having a split shell configuration. Only one vapor stripping feed is required to the split shell of the fractionation column. The resulting reduction in steam requirement provides a superior fractionation in the column. Full Article
nuc POLYNUCLEOTIDE AGENTS TARGETING COMPLEMENT COMPONENT C5 AND METHODS OF USE THEREOF By www.freepatentsonline.com Published On :: Thu, 29 Jun 2017 08:00:00 EDT The invention relates to polynucleotide agents targeting the complement component C5 gene, and methods of using such polynucleotide agents to inhibit expression of C5 and to treat subjects having a complement component C5-associated disease, e.g., paroxysmal nocturnal hemoglobinuria. Full Article
nuc EXOSOMAL LOADING USING HYDROPHOBICALLY MODIFIED OLIGONUCLEOTIDES By www.freepatentsonline.com Published On :: Thu, 29 Jun 2017 08:00:00 EDT In one aspect, the invention relates to a method of loading exosomes with oligonucleotide cargo, by incubating an oligonucleotide comprising one or more hydrophobic modifications with a population of exosomes for a period of time sufficient to allow loading of the exosomes with the oligonucleotide. Exosomes loaded with hydrophobic ally modified oligonucleotide cargo, and uses thereof, are also provided. Full Article
nuc COMPOSITIONS AND METHODS FOR MODIFYING A PREDETERMINED TARGET NUCLEIC ACID SEQUENCE By www.freepatentsonline.com Published On :: Thu, 29 Jun 2017 08:00:00 EDT Provided herein are compositions and methods for modifying a predetermined nucleic acid sequence. A programmable nucleoprotein molecular complex containing a polypeptide moiety and a specificity conferring nucleic acid (SCNA) which assembles in-vivo, in a target cell, and is capable of interacting with the predetermined target nucleic acid sequence is provided. The programmable nucleoprotein molecular complex is capable of specifically modifying and/or editing a target site within the target nucleic acid sequence and/or modifying the function of the target nucleic acid sequence. Full Article
nuc SYSTEMS AND METHODS FOR TAILORED MICROSTRUCTURES USING TEMPLATED GRAIN NUCLEATION By www.freepatentsonline.com Published On :: Thu, 29 Jun 2017 08:00:00 EDT Methods for controlled microstructure creation utilize seeding of amorphous layers prior to annealing. Seed crystals are formed on an amorphous layer or layers. The material, size, and spacing of the seed crystals may be varied, and multiple seed layers and/or amorphous layers may be utilized. Thereafter, the resulting assembly is annealed to generate a crystalline microstructure. Via use of these methods, devices having desirable microstructural properties are enabled. Full Article
nuc Enhanced Boiling with Selective Placement of Nucleation Sites By www.freepatentsonline.com Published On :: Thu, 22 Jun 2017 08:00:00 EDT A heat transfer system includes a substrate having a heat exchange region including a surface having an enhancement region including alternating regions of selectively placed plurality of nucleation sites and regions lacking selectively placed nucleation sites, such that bubble formation and departure during boiling of a liquid in contact with the enhancement region induces liquid motion over the surface of the regions lacking selectively placed nucleation sites sufficient to enhance both critical heat flux and heat transfer coefficient at the critical heat flux in the enhancement region of the system. Full Article
nuc Axl Rose Cursing at Steve Mnuchin on Twitter By www.aceshowbiz.com Published On :: Thu, 07 May 2020 20:45:02 +0000 The Guns N' Roses rocker is embroiled in an online spat with the U.S. Secretary of the Treasury after putting the latter on blast in a foul-mouthed post on social media. Full Article celebrity Axl Rose
nuc Deja Nuke: Return of the Nuclear Threat By reveal.prx.org Published On :: Sat, 03 Mar 2018 05:05:41 -0000 With the threat of nuclear war once again a part of the national conversation, Reveal looks at nuclear threats both foreign and domestic. This episode takes listeners to Iran and finds out what life is actually like inside North Korea. As the Trump administration pushes for the biggest increase in spending on nuclear weapons since the Cold War, Reveal explores how they’ve changed. Instead of annihilation, think “flexible” nuclear weapons that can threaten “limited” nuclear war. That’s the idea anyway. Head over to revealnews.org for more of our reporting. Follow us on Facebook at fb.com/ThisIsReveal and on Twitter @reveal. And to see some of what you’re hearing, we’re also on Instagram @revealnews. Full Article Al Letson Arizona Donald Trump Emily Harris Foreign Policy Foreign Relations History International Relations Interview Iran Kim Jong Un Korea Korean Peninsula Mid-East Politics Middle East Military News & Politics North Korea Nuclear War Nuclear Weapons Nukes Podcast Politics Reese Erlich Suki Kim Technology The Day After Threat Assessment Titan Missle Tucson War
nuc Axl Rose, Steven Mnuchin and the pandemic Twitter feud no one saw coming By www.seattletimes.com Published On :: Thu, 07 May 2020 06:12:15 -0700 By all accounts, 2020 has been, to put it mildly, a weird year. This week alone has already seen a 5-year-old boy from Utah attempt a solo drive to California on a mission to buy a Lamborghini, a llama named Winter emerge as a potential key player in the race for a treatment targeting the […] Full Article Entertainment Music Nation Nation & World Nation & World Politics Oddities Technology
nuc Axl Rose, Steven Mnuchin and the pandemic Twitter feud no one saw coming By www.seattletimes.com Published On :: Thu, 07 May 2020 06:12:15 -0700 By all accounts, 2020 has been, to put it mildly, a weird year. This week alone has already seen a 5-year-old boy from Utah attempt a solo drive to California on a mission to buy a Lamborghini, a llama named Winter emerge as a potential key player in the race for a treatment targeting the […] Full Article Entertainment Music Nation Nation & World Nation & World Politics Oddities Technology
nuc Official: US must move ahead with nuclear weapons work By www.seattletimes.com Published On :: Wed, 06 May 2020 12:52:54 -0700 ALBUQUERQUE, N.M. (AP) — A top nuclear security official says the U.S. must move ahead with plans to ramp up production of key components for the nation’s nuclear arsenal despite the challenges presented by the coronavirus. Federal officials have set a deadline of 2030 for increased production of the plutonium cores used in nuclear weapons. […] Full Article Business Health Nation Science
nuc Official: US must move ahead with nuclear weapons work By www.seattletimes.com Published On :: Wed, 06 May 2020 12:52:54 -0700 ALBUQUERQUE, N.M. (AP) — A top nuclear security official says the U.S. must move ahead with plans to ramp up production of key components for the nation’s nuclear arsenal despite the challenges presented by the coronavirus. Federal officials have set a deadline of 2030 for increased production of the plutonium cores used in nuclear weapons. […] Full Article Business Health Nation Science
nuc Axl Rose, Steven Mnuchin and the pandemic Twitter feud no one saw coming By www.seattletimes.com Published On :: Thu, 07 May 2020 06:12:15 -0700 By all accounts, 2020 has been, to put it mildly, a weird year. This week alone has already seen a 5-year-old boy from Utah attempt a solo drive to California on a mission to buy a Lamborghini, a llama named Winter emerge as a potential key player in the race for a treatment targeting the […] Full Article Entertainment Music Nation Nation & World Nation & World Politics Oddities Technology
nuc How far are we from a nuclear fusion future? By www.abc.net.au Published On :: Sun, 29 Mar 2020 10:30:00 +1100 The hope of nuclear fusion is the dream of a fossil-fuel free future - of limitless baseload power. Enthusiasts say fusion offers all the benefits of nuclear energy without the dangers. In theory and in practice fusion energy is already a reality, but getting the economics right is proving much more difficult than imagined. Full Article Nuclear Energy Science and Technology
nuc Nuclear reactor and steelworks plan once considered for pristine beaches of Jervis Bay By www.abc.net.au Published On :: Mon, 12 Aug 2019 14:13:00 +1000 Jervis Bay one of Australia's world-renowned coastal tourist hotspots, celebrated for its idyllic white beaches, nearly became home to Australia's first nuclear power plant. Full Article 1233 ABC Newcastle canberra illawarra newcastle Community and Society:History:All Environment:Alternative Energy:Nuclear Energy Environment:Environmental Policy:All Environment:Nuclear Issues:All Government and Politics:Federal - State Issues:All Australia:ACT:Canberra 2600 Australia:ACT:Jervis Bay 2540 Australia:NSW:Newcastle 2300 Australia:NSW:Nowra 2541 Australia:NSW:University of Newcastle 2308 Australia:NSW:Wollongong 2500
nuc Nuclear waste site selection process triggers mental health concerns, business boycotts and division, FOI documents reveal By www.abc.net.au Published On :: Wed, 13 Feb 2019 19:19:00 +1100 FOI documents also reveal the Federal Government knows the process is creating division in small towns and causing some businesses to be boycotted. Full Article ABC Eyre Peninsula and West Coast canberra adelaide northandwest eyre Education:Subjects:Science Environment:All:All Environment:Nuclear Issues:All Government and Politics:Federal Government:All Australia:ACT:Canberra 2600 Australia:All:All Australia:SA:Adelaide 5000 Australia:SA:Hawker 5434 Australia:SA:Kimba 5641 Australia:SA:Port Augusta 5700 Australia:SA:Port Lincoln 5606 Australia:SA:Port Pirie 5540 Australia:SA:Whyalla 5600
nuc Outback WA council keeps hand raised for nuclear waste facility, as legal action halts progress on SA sites By www.abc.net.au Published On :: Tue, 12 Mar 2019 11:37:00 +1100 Leonora, a small town in the West Australian Goldfields, is being touted as a suitable location for an underground, low and intermediate-level nuclear waste storage facility. Full Article ABC Eyre Peninsula and West Coast sydney adelaide northandwest eyre goldfields perth Community and Society:Regional:All Environment:Environmental Management:All Environment:Nuclear Issues:All Government and Politics:All:All Human Interest:People:All Australia:All:All Australia:NSW:Lucas Heights 2234 Australia:NSW:Sydney 2000 Australia:SA:Adelaide 5000 Australia:SA:All Australia:SA:Hawker 5434 Australia:SA:Kimba 5641 Australia:SA:Port Augusta 5700 Australia:SA:Port Lincoln 5606 Australia:SA:Port Pirie 5540 Australia:SA:Whyalla 5600 Australia:WA:All Australia:WA:Kalgoorlie 6430 Australia:WA:Leonora 6438 Australia:WA:Perth 6000
nuc Will Australia finally get a national nuclear waste facility? By www.abc.net.au Published On :: Thu, 28 Mar 2019 18:36:00 +1100 Legal action is threatening the latest proposed sites for storing nuclear waste in South Australia, and the debate is dividing communities and traditional owners. Full Article ABC Eyre Peninsula and West Coast northandwest eyre Community and Society:Indigenous (Aboriginal and Torres Strait Islander):All Environment:Nuclear Issues:All Environment:Recycling and Waste Management:All Law Crime and Justice:Rights:Native Title Australia:SA:Hawker 5434 Australia:SA:Kimba 5641
nuc Federal Court dismisses bid to stop ballot on nuclear storage facility near Kimba By www.abc.net.au Published On :: Fri, 12 Jul 2019 14:03:00 +1000 A South Australian Aboriginal group loses a bid to stop a council ballot on whether a nuclear storage facility should be built on the Eyre Peninsula. Full Article ABC Eyre Peninsula and West Coast adelaide eyre northandwest Community and Society:All:All Community and Society:Indigenous (Aboriginal and Torres Strait Islander):Aboriginal Community and Society:Indigenous (Aboriginal and Torres Strait Islander):All Environment:All:All Environment:Nuclear Issues:All Government and Politics:Local Government:All Law Crime and Justice:All:All Law Crime and Justice:Rights:All Law Crime and Justice:Rights:Native Title Australia:All:All Australia:SA:Adelaide 5000 Australia:SA:All Australia:SA:Kimba 5641 Australia:SA:Port Augusta 5700 Australia:SA:Port Lincoln 5606
nuc Maralinga nuclear test site used to house thousands of people, now there's just three By www.abc.net.au Published On :: Sat, 19 Oct 2019 07:30:00 +1100 Thousands of scientists and soldiers once lived at the Maralinga nuclear site, but now it's home to just three people who are in love with the country. Full Article ABC Eyre Peninsula and West Coast eyre northandwest Community and Society:All:All Community and Society:History:20th Century Community and Society:History:All Community and Society:Indigenous (Aboriginal and Torres Strait Islander):Aboriginal Community and Society:Indigenous (Aboriginal and Torres Strait Islander):All Community and Society:Indigenous (Aboriginal and Torres Strait Islander):Land Rights Community and Society:Regional:All Defence and National Security:All:All Defence and National Security:Defence Forces:All Environment:Nuclear Issues:All Government and Politics:Indigenous Policy:All Human Interest:People:All Australia:SA:Ceduna 5690 Australia:SA:Port Augusta 5700 Australia:SA:Port Lincoln 5606 Australia:SA:Port Pirie 5540 Australia:SA:Whyalla 5600 Australia:SA:Yalata 5690 United Kingdom:All:All
nuc Event with MMA, boxing, bare-knuckle fighting set for June 6 in Kansas By www.thescore.com Published On :: Tue, 05 May 2020 18:57:15 +0000 Full Article
nuc Tyson offered $20M to compete in bare-knuckle boxing By www.thescore.com Published On :: Thu, 07 May 2020 14:46:15 +0000 Full Article
nuc Jim Danley, Colorado’s winningest prep baseball coach, built Eaton dynasty off the knuckle-curve and a farm system By www.denverpost.com Published On :: Sun, 26 Apr 2020 12:00:00 +0000 In 44 seasons as Eaton's head coach from 1972 to 2015, Danley was 807-163-2, a Colorado-best for wins and tied for the nation's top prep winning percentage (83.1%). Full Article Latest News Preps Sports Bob Bote CHSAA Colorado Sports Hall of Fame Eaton High School Faith Christian Marc Johnson Prep baseball
nuc Smaller Detection Device Effective for Nuclear Treaty Verification, Archaeology Digs By feedproxy.google.com Published On :: Wed, 29 Jan 2020 15:20:30 EST Most nuclear data measurements are performed at accelerators large enough to occupy a geologic formation a kilometer wide. But a portable device that can reveal the composition of materials quickly on-site would greatly benefit cases such as in archaeology and nuclear arms treaty verification. Research published this week in AIP Advances used computational simulations to show that with the right geometric adjustments, it is possible to perform accurate neutron resonance transmission analysis in a device just 5 meters long. Full Article
nuc ‘Nuclear pasta’ might be the strongest stuff in the known universe By www.pbs.org Published On :: Neutron star innards are not your mom’s lasagna. Full Article
nuc Kings trade Tyler Toffoli to Canucks for two players and two draft picks By www.latimes.com Published On :: Tue, 18 Feb 2020 00:29:11 -0500 Tyler Toffoli, who scored a hat trick in his last game with the Kings on Saturday, was traded to the Vancouver Canucks on Monday. Full Article
nuc Elite private schools are receiving federal loans — including one attended by Secretary Mnuchin's children By www.latimes.com Published On :: Thu, 30 Apr 2020 22:56:40 -0400 Among the elite private schools that have received federal loans amid COVID-19 is the Brentwood School in West L.A., which Mnuchin's children attend. Full Article
nuc Trump and Mnuchin pressure well-heeled private schools to return federal loans By www.latimes.com Published On :: Fri, 1 May 2020 15:30:13 -0400 President Trump and Treasury Secretary Mnuchin say elite private schools with significant endowments shouldn't get Paycheck Protection Program loans. Full Article
nuc Brentwood School returns federal aid after Trump, Mnuchin criticism By www.latimes.com Published On :: Mon, 4 May 2020 22:14:20 -0400 The exclusive Brentwood School has returned money it received under the Paycheck Protection Program after President Trump and Treasury Secretary Mnuchin leveled criticism at private schools that took funds from the federal coronavirus aid program. Full Article
nuc North Korea nuclear alert: Satellite images reveal despot Kim's terrifying plot By feedproxy.google.com Published On :: Sat, 09 May 2020 00:11:00 +0100 KIM JONG-UN is building a massive facility outside the capital Pyongyang, satellite images have shown, suggesting he is planning to beef up his stockpile of nuclear weapons. Full Article
nuc Iran nuclear report: Regurgitating old stories as new information to justify sanctions? By www.globalissues.org Published On :: Tue, 06 Dec 2011 05:20:00 GMT A recent IAEA report on Iran’s nuclear program was portrayed by most Western mainstream media and politicians as new proof Iran is close to building nuclear weapons. The US Senate passed sanctions on Iran targeting its central bank in response. However, the report does not say what the mainstream media and politicians claim. It has been much more guarded and much of it is about the state of Iran’s program up to 2003. After that period, the report is much more uncertain. Furthermore, many experts contend that the speculations (not definitive proof) that are in the report are misguided, too, leaning on unreliable sources, for example. This update to the page on Iran has more information about this. Although the page is long, look for the new section about half way down under the heading of Regurgitating old stories as new information to justify sanctions? Read full article: Iran Full Article Nuclear Weapons Middle East
nuc Những chuyện nực cười trong cái chết của Stalin By www.bbc.com Published On :: Tue, 12 Feb 2019 08:57:10 GMT Bộ phim Cái chết của Stalin của đạo diễn Armando Iannucci đặt ra một câu hỏi có thể ứng với nhiều quốc gia khác trong lịch sử. Full Article
nuc {alpha}-Synuclein filaments from transgenic mouse and human synucleinopathy-containing brains are maȷor seed-competent species [Molecular Bases of Disease] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 Assembled α-synuclein in nerve cells and glial cells is the defining pathological feature of neurodegenerative diseases called synucleinopathies. Seeds of α-synuclein can induce the assembly of monomeric protein. Here, we used sucrose gradient centrifugation and transiently transfected HEK 293T cells to identify the species of α-synuclein from the brains of homozygous, symptomatic mice transgenic for human mutant A53T α-synuclein (line M83) that seed aggregation. The most potent fractions contained Sarkosyl-insoluble assemblies enriched in filaments. We also analyzed six cases of idiopathic Parkinson's disease (PD), one case of familial PD, and six cases of multiple system atrophy (MSA) for their ability to induce α-synuclein aggregation. The MSA samples were more potent than those of idiopathic PD in seeding aggregation. We found that following sucrose gradient centrifugation, the most seed-competent fractions from PD and MSA brains are those that contain Sarkosyl-insoluble α-synuclein. The fractions differed between PD and MSA, consistent with the presence of distinct conformers of assembled α-synuclein in these different samples. We conclude that α-synuclein filaments are the main driving force for amplification and propagation of pathology in synucleinopathies. Full Article
nuc Risk of serious cyber attacks on nuclear facilities underestimated, says new report By feedproxy.google.com Published On :: Fri, 09 Oct 2015 15:22:30 +0000 2 October 2015 20150930CyberSecurity.jpg Workers at the Wolsong nuclear power plant participate in an anti-cyber attack exercise, Gyeongju, South Korea. Photo: Getty Images. The risk of a serious cyber attack on civil nuclear infrastructure is growing, as facilities become ever more reliant on digital systems and make increasing use of commercial ‘off-the-shelf’ software, according to a major new report from Chatham House.Cyber Security at Civil Nuclear Facilities: Understanding the Risks is the result of an 18-month study that draws on in-depth interviews with 30 leading industry practitioners based in more than eight countries. It found that the trend to digitization, when combined with a lack of executive-level awareness of the risks involved, means that nuclear plant personnel may not realize the full extent of their cyber vulnerability and are thus inadequately prepared to deal with potential attacks. Specific findings include: The conventional belief that all nuclear facilities are ‘air gapped’ (isolated from the public internet) is a myth. The commercial benefits of internet connectivity mean that a number of nuclear facilities now have VPN connections installed, which facility operators are sometimes unaware of.Search engines can readily identify critical infrastructure components with such connections.Even where facilities are air gapped, this safeguard can be breached with nothing more than a flash drive.Supply chain vulnerabilities mean that equipment used at a nuclear facility risks compromise at any stage.A lack of training, combined with communication breakdowns between engineers and security personnel, means that nuclear plant personnel often lack an understanding of key cyber security procedures.Reactive rather than proactive approaches to cyber security contribute to the possibility that a nuclear facility might not know of a cyber attack until it is already substantially under way.In the light of these risks, the report outlines a blend of policy and technical measures that will be required to counter the threats and meet the challenges. Recommendations include:Developing guidelines to measure cyber security risk in the nuclear industry, including an integrated risk assessment that takes both security and safety measures into account.Engaging in robust dialogue with engineers and contractors to raise awareness of the cyber security risk, including the dangers of setting up unauthorized internet connections.Implementing rules, where not already in place, to promote good IT hygiene in nuclear facilities (for example to forbid the use of personal devices) and enforcing rules where they do exist.Improving disclosure by encouraging anonymous information sharing and the establishment of industrial CERTs (Computer Emergency Response Team).Encouraging universal adoption of regulatory standards. Editor's notes Cyber Security at Civil Nuclear Facilities: Understanding the Risks, written by Caroline Baylon with Roger Brunt and David Livingstone, is embargoed until Monday 5 October 2015.Caroline Baylon is the research associate in science, technology and cyber security at Chatham House. Roger Brunt was appointed the UK government's regulator for security in the civil nuclear industry as the director of the Office for Civil Nuclear Security after retiring from the British Army in 2004. David Livingstone is an associate fellow at Chatham House, where he has participated in a broad range of projects on national-level risk management, cyber security, counterterrorism, serious organized crime, nuclear security and space security.Fore more information, or to request an interview with the authors, contact the press office Contacts Press Office +44 (0)20 7957 5739 Email Full Article
nuc Impact of 1,N6-ethenoadenosine, a damaged ribonucleotide in DNA, on translesion synthesis and repair [Enzymology] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 Incorporation of ribonucleotides into DNA can severely diminish genome integrity. However, how ribonucleotides instigate DNA damage is poorly understood. In DNA, they can promote replication stress and genomic instability and have been implicated in several diseases. We report here the impact of the ribonucleotide rATP and of its naturally occurring damaged analog 1,N6-ethenoadenosine (1,N6-ϵrA) on translesion synthesis (TLS), mediated by human DNA polymerase η (hpol η), and on RNase H2–mediated incision. Mass spectral analysis revealed that 1,N6-ϵrA in DNA generates extensive frameshifts during TLS, which can lead to genomic instability. Moreover, steady-state kinetic analysis of the TLS process indicated that deoxypurines (i.e. dATP and dGTP) are inserted predominantly opposite 1,N6-ϵrA. We also show that hpol η acts as a reverse transcriptase in the presence of damaged ribonucleotide 1,N6-ϵrA but has poor RNA primer extension activities. Steady-state kinetic analysis of reverse transcription and RNA primer extension showed that hpol η favors the addition of dATP and dGTP opposite 1,N6-ϵrA. We also found that RNase H2 recognizes 1,N6-ϵrA but has limited incision activity across from this lesion, which can lead to the persistence of this detrimental DNA adduct. We conclude that the damaged and unrepaired ribonucleotide 1,N6-ϵrA in DNA exhibits mutagenic potential and can also alter the reading frame in an mRNA transcript because 1,N6-ϵrA is incompletely incised by RNase H2. Full Article
nuc It takes two (Las1 HEPN endoribonuclease domains) to cut RNA correctly [RNA] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 The ribosome biogenesis factor Las1 is an essential endoribonuclease that is well-conserved across eukaryotes and a newly established member of the higher eukaryotes and prokaryotes nucleotide-binding (HEPN) domain-containing nuclease family. HEPN nucleases participate in diverse RNA cleavage pathways and share a short HEPN nuclease motif (RφXXXH) important for RNA cleavage. Most HEPN nucleases participate in stress-activated RNA cleavage pathways; Las1 plays a fundamental role in processing pre-rRNA. Underscoring the significance of Las1 function in the cell, mutations in the human LAS1L (LAS1-like) gene have been associated with neurological dysfunction. Two juxtaposed HEPN nuclease motifs create Las1's composite nuclease active site, but the roles of the individual HEPN motif residues are poorly defined. Here using a combination of in vivo experiments in Saccharomyces cerevisiae and in vitro assays, we show that both HEPN nuclease motifs are required for Las1 nuclease activity and fidelity. Through in-depth sequence analysis and systematic mutagenesis, we determined the consensus HEPN motif in the Las1 subfamily and uncovered its canonical and specialized elements. Using reconstituted Las1 HEPN-HEPN' chimeras, we defined the molecular requirements for RNA cleavage. Intriguingly, both copies of the Las1 HEPN motif were important for nuclease function, revealing that both HEPN motifs participate in coordinating the RNA within the Las1 active site. We also established that conformational flexibility of the two HEPN domains is important for proper nuclease function. The results of our work reveal critical information about how dual HEPN domains come together to drive Las1-mediated RNA cleavage. Full Article
nuc Quantification of the affinities of CRISPR-Cas9 nucleases for cognate protospacer adȷacent motif (PAM) sequences [Molecular Biophysics] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 The CRISPR/Cas9 nucleases have been widely applied for genome editing in various organisms. Cas9 nucleases complexed with a guide RNA (Cas9–gRNA) find their targets by scanning and interrogating the genomic DNA for sequences complementary to the gRNA. Recognition of the DNA target sequence requires a short protospacer adjacent motif (PAM) located outside this sequence. Given that the efficiency of target location may depend on the strength of interactions that promote target recognition, here we sought to compare affinities of different Cas9 nucleases for their cognate PAM sequences. To this end, we measured affinities of Cas9 nucleases from Streptococcus pyogenes, Staphylococcus aureus, and Francisella novicida complexed with guide RNAs (gRNAs) (SpCas9–gRNA, SaCas9–gRNA, and FnCas9–gRNA, respectively) and of three engineered SpCas9–gRNA variants with altered PAM specificities for short, PAM-containing DNA probes. We used a “beacon” assay that measures the relative affinities of DNA probes by determining their ability to competitively affect the rate of Cas9–gRNA binding to fluorescently labeled target DNA derivatives called “Cas9 beacons.” We observed significant differences in the affinities for cognate PAM sequences among the studied Cas9 enzymes. The relative affinities of SpCas9–gRNA and its engineered variants for canonical and suboptimal PAMs correlated with previous findings on the efficiency of these PAM sequences in genome editing. These findings suggest that high affinity of a Cas9 nuclease for its cognate PAM promotes higher genome-editing efficiency. Full Article
nuc Perspectives on Nuclear Deterrence in the 21st Century By feedproxy.google.com Published On :: Sun, 19 Apr 2020 19:32:28 +0000 20 April 2020 Nuclear deterrence theory, with its roots in the Cold War era, may not account for all eventualities in the 21st century. Researchers at Chatham House have worked with eight experts to produce this collection of essays examining four contested themes in contemporary policymaking on deterrence. Read online Download PDF Dr Beyza Unal Senior Research Fellow, International Security Programme @beyzaunal Google Scholar Yasmin Afina Research Assistant, International Security Programme @afinayasmin LinkedIn Dr Patricia Lewis Research Director, Conflict, Science & Transformation; Director, International Security Programme @PatriciaMary Dr John Borrie Associate Fellow, International Security Programme Google Scholar Dr Jamie Shea Associate Fellow, International Security Programme LinkedIn Peter Watkins Associate Fellow, International Security Programme LinkedIn Dr Maria Rost Rublee Associate Professor of International Relations, Monash University Cristina Varriale Research Fellow in Proliferation and Nuclear Policy, RUSI Dr Tanya Ogilvie-White Adjunct Senior Fellow, Griffith Asia Institute, Griffith University Dr Andrew Futter Associate Professor of International Politics, University of Leicester Christine Parthemore Chief Executive Officer, Council on Strategic Risks (CSR) 2020-04-20-NuclearDeterrence.jpeg Royal Navy Vanguard Class submarine HMS Vigilant returning to HMNB Clyde after extended deployment. The four Vanguard-class submarines form the UK's strategic nuclear deterrent force. Photo: Ministry of Defence. SummaryThis collection of essays explores, from the perspectives of eight experts, four areas of deterrence theory and policymaking: the underlying assumptions that shape deterrence practice; the enduring value of extended deterrence; the impact of emerging technologies; and the ‘blurring’ of the lines between conventional and nuclear weapons.Nuclear deterrence theory, with its roots in the Cold War era, may not account for all eventualities in security and defence in the 21st century, given the larger number of nuclear actors in a less binary geopolitical context. It is clear that a number of present factors challenge the overall credibility of ‘classical’ nuclear deterrence, meaning that in-depth analysis is now needed.Uncertainty as to the appetite to maintain the current nuclear weapons policy architecture looms large in discussions and concerns on global and regional security. The demise of the Intermediate-Range Nuclear Forces Treaty, doubts over the potential extension of the New Strategic Arms Reduction Treaty, heightened regional tensions in Northeast and South Asia, together with the current and likely future risks and challenges arising from global technological competition, making it all the more urgent to examine long-held assumptions in the real-world context.Extended deterrence practices differ from region to region, depending on the domestic and regional landscape. Increased focus on diplomatic capabilities to reduce risks and improve the long-term outlook at regional level, including by spearheading new regional arms-control initiatives, may be a viable way forward. Addressing the bigger picture – notably including, on the Korean peninsula, Pyongyang’s own threat perception – and the links between conventional and nuclear missile issues will need to remain prominent if long-term and concrete changes are to take hold.Most states have long held nuclear weapons to be ‘exceptional’: their use would represent a dramatic escalation of a conflict that must never be attained. Latterly, however, some officials and scholars have made the case that the impact of the use of a low-yield nuclear weapon would not be entirely distinct from that of a large-scale conventional attack. This blurring of lines between conventional and nuclear deterrence strips nuclear weapons of their exceptional nature, in a context in which states are faced with diverse, complex and concurrent threats from multiple potential adversaries that are able to synchronize non-military and military options, up to and including nuclear forces. The use of nuclear weapons risks becoming a ‘new normal’, potentially reducing the threshold for use – to cyberattacks, for example. This has direct implications for discussions around strategic stability. While emerging technologies may offer tremendous opportunities in the modernization of nuclear weapons, they also present major risks and destabilizing challenges. Artificial intelligence, automation, and other developments in the cyber sphere affect dynamics on both the demand and supply sides of the nuclear deterrence equation. States and alliance such as NATO must adapt their deterrence thinking in light of these technological developments, and define their primary purpose and priorities in this shifting security context. Resilience planning, adaptation to the evolving security environment, threat anticipation, and consistent crisis management and incident response – as well as thinking about the mitigation measures necessary to prevent conflict escalation should deterrence fail – will all be critical in upholding nuclear deterrence as both policy and practice. Department/project International Security Programme, Deterrence Perspectives in the 21st Century Full Article
nuc Nuclear Tensions Must Not Be Sidelined During Coronavirus By feedproxy.google.com Published On :: Fri, 01 May 2020 11:18:35 +0000 1 May 2020 Ana Alecsandru Research Assistant, International Security Programme @anaalecs LinkedIn Although the pandemic means the Nuclear Non-Proliferation Treaty (NPT) Review Conference (RevCon) is postponed, the delay could be an opportunity to better the health of the NPT regime. 2020-05-01-Iran-Peace-Nuclear Painted stairs in Tehran, Iran symbolizing hope. Photo by Fatemeh Bahrami/Anadolu Agency/Getty Images. Despite face-to-face diplomatic meetings being increasingly rare during the current disruption, COVID-19 will ultimately force a redefinition of national security and defence spending priorities, and this could provide the possibility of an improved political climate at RevCon when it happens in 2021.With US presidential elections due in November and a gradual engagement growing between the EU and Iran, there could be a new context for more cooperation between states by 2021. Two key areas of focus over the coming months will be the arms control talks between the United States and Russia, and Iran’s compliance with the 2015 Joint Comprehensive Plan of Action (JCPOA), also known as the Iran Nuclear Deal.It is too early to discern the medium- and longer-term consequences of COVID-19 for defence ministries, but a greater focus on societal resilience and reinvigorating economic productivity will likely undercut the rationale for expensive nuclear modernization.Therefore, extending the current New START (Strategic Arms Reduction Treaty) would be the best, most practical option to give both Russia and the United States time to explore more ambitious multilateral arms control measures, while allowing their current focus to remain on the pandemic and economic relief.Continuing distrustBut with the current treaty — which limits nuclear warheads, missiles, bombers, and launchers — due to expire in February 2021, the continuing distrust between the United States and Russia makes this extension hard to achieve, and a follow-on treaty even less likely.Prospects for future bilateral negotiations are hindered by President Donald Trump’s vision for a trilateral arms control initiative involving both China and Russia. But China opposes this on the grounds that its nuclear arsenal is far smaller than that of the two others.While there appears to be agreement that the nuclear arsenals of China, France, and the UK (the NPT nuclear-weapons states) and those of the states outside the treaty (India, Pakistan, North Korea, and Israel) will all have to be taken into account going forward, a practical mechanism for doing so proves elusive.If Joe Biden wins the US presidency he seems likely to pursue an extension of the New START treaty and could also prevent a withdrawal from the Open Skies treaty, the latest arms control agreement targeted by the Trump administration.Under a Biden administration, the United States would also probably re-join the JCPOA, provided Tehran returned to strict compliance with the deal. Biden could even use the team that negotiated the Iran deal to advance the goal of denuclearization of the Korean peninsula.For an NPT regime already confronted by a series of longstanding divergences, it is essential that Iran remains a signatory especially as tensions between Iran and the United States have escalated recently — due to the Qassim Suleimani assassination and the recent claim by Iran’s Revolutionary Guard Corps to have successfully placed the country’s first military satellite into orbit.This announcement raised red flags among experts about whether Iran is developing intercontinental ballistic missiles due to the dual-use nature of space technology. The satellite launch — deeply troubling for Iran’s neighbours and the EU countries — may strengthen the US argument that it is a cover for the development of ballistic missiles capable of delivering nuclear weapons.However, as with many other countries, Iran is struggling with a severe coronavirus crisis and will be pouring its scientific expertise and funds into that rather than other efforts — including the nuclear programme.Those European countries supporting the trading mechanism INSTEX (Instrument in Support of Trade Exchanges) for sending humanitarian goods into Iran could use this crisis to encourage Iran to remain in compliance with the JCPOA and its NPT obligations.France, Germany and the UK (the E3) have already successfully concluded the first transaction, which was to facilitate the export of medical goods from Europe to Iran. But the recent Iranian escalatory steps will most certainly place a strain on the preservation of this arrangement.COVID-19 might have delayed Iran’s next breach of the 2015 nuclear agreement but Tehran will inevitably seek to strengthen its hand before any potential negotiations with the United States after the presidential elections.As frosty US-Iranian relations — exacerbated by the coronavirus pandemic — prevent diplomatic negotiations, this constructive engagement between the E3 and Iran might prove instrumental in reviving the JCPOA and ensuring Iran stays committed to both nuclear non-proliferation and disarmament.While countries focus their efforts on tackling the coronavirus pandemic, it is understandable resources may be limited for other global challenges, such as the increasing risk of nuclear weapons use across several regions.But the potential ramifications of the COVID-19 crisis for the NPT regime are profound. Ongoing tensions between the nuclear-armed states must not be ignored while the world’s focus is elsewhere, and the nuclear community should continue to work together to progress nuclear non-proliferation and disarmament, building bridges of cooperation and trust that can long outlast the pandemic. Full Article
nuc Nuclear Tensions Must Not Be Sidelined During Coronavirus By feedproxy.google.com Published On :: Fri, 01 May 2020 11:18:35 +0000 1 May 2020 Ana Alecsandru Research Assistant, International Security Programme @anaalecs LinkedIn Although the pandemic means the Nuclear Non-Proliferation Treaty (NPT) Review Conference (RevCon) is postponed, the delay could be an opportunity to better the health of the NPT regime. 2020-05-01-Iran-Peace-Nuclear Painted stairs in Tehran, Iran symbolizing hope. Photo by Fatemeh Bahrami/Anadolu Agency/Getty Images. Despite face-to-face diplomatic meetings being increasingly rare during the current disruption, COVID-19 will ultimately force a redefinition of national security and defence spending priorities, and this could provide the possibility of an improved political climate at RevCon when it happens in 2021.With US presidential elections due in November and a gradual engagement growing between the EU and Iran, there could be a new context for more cooperation between states by 2021. Two key areas of focus over the coming months will be the arms control talks between the United States and Russia, and Iran’s compliance with the 2015 Joint Comprehensive Plan of Action (JCPOA), also known as the Iran Nuclear Deal.It is too early to discern the medium- and longer-term consequences of COVID-19 for defence ministries, but a greater focus on societal resilience and reinvigorating economic productivity will likely undercut the rationale for expensive nuclear modernization.Therefore, extending the current New START (Strategic Arms Reduction Treaty) would be the best, most practical option to give both Russia and the United States time to explore more ambitious multilateral arms control measures, while allowing their current focus to remain on the pandemic and economic relief.Continuing distrustBut with the current treaty — which limits nuclear warheads, missiles, bombers, and launchers — due to expire in February 2021, the continuing distrust between the United States and Russia makes this extension hard to achieve, and a follow-on treaty even less likely.Prospects for future bilateral negotiations are hindered by President Donald Trump’s vision for a trilateral arms control initiative involving both China and Russia. But China opposes this on the grounds that its nuclear arsenal is far smaller than that of the two others.While there appears to be agreement that the nuclear arsenals of China, France, and the UK (the NPT nuclear-weapons states) and those of the states outside the treaty (India, Pakistan, North Korea, and Israel) will all have to be taken into account going forward, a practical mechanism for doing so proves elusive.If Joe Biden wins the US presidency he seems likely to pursue an extension of the New START treaty and could also prevent a withdrawal from the Open Skies treaty, the latest arms control agreement targeted by the Trump administration.Under a Biden administration, the United States would also probably re-join the JCPOA, provided Tehran returned to strict compliance with the deal. Biden could even use the team that negotiated the Iran deal to advance the goal of denuclearization of the Korean peninsula.For an NPT regime already confronted by a series of longstanding divergences, it is essential that Iran remains a signatory especially as tensions between Iran and the United States have escalated recently — due to the Qassim Suleimani assassination and the recent claim by Iran’s Revolutionary Guard Corps to have successfully placed the country’s first military satellite into orbit.This announcement raised red flags among experts about whether Iran is developing intercontinental ballistic missiles due to the dual-use nature of space technology. The satellite launch — deeply troubling for Iran’s neighbours and the EU countries — may strengthen the US argument that it is a cover for the development of ballistic missiles capable of delivering nuclear weapons.However, as with many other countries, Iran is struggling with a severe coronavirus crisis and will be pouring its scientific expertise and funds into that rather than other efforts — including the nuclear programme.Those European countries supporting the trading mechanism INSTEX (Instrument in Support of Trade Exchanges) for sending humanitarian goods into Iran could use this crisis to encourage Iran to remain in compliance with the JCPOA and its NPT obligations.France, Germany and the UK (the E3) have already successfully concluded the first transaction, which was to facilitate the export of medical goods from Europe to Iran. But the recent Iranian escalatory steps will most certainly place a strain on the preservation of this arrangement.COVID-19 might have delayed Iran’s next breach of the 2015 nuclear agreement but Tehran will inevitably seek to strengthen its hand before any potential negotiations with the United States after the presidential elections.As frosty US-Iranian relations — exacerbated by the coronavirus pandemic — prevent diplomatic negotiations, this constructive engagement between the E3 and Iran might prove instrumental in reviving the JCPOA and ensuring Iran stays committed to both nuclear non-proliferation and disarmament.While countries focus their efforts on tackling the coronavirus pandemic, it is understandable resources may be limited for other global challenges, such as the increasing risk of nuclear weapons use across several regions.But the potential ramifications of the COVID-19 crisis for the NPT regime are profound. Ongoing tensions between the nuclear-armed states must not be ignored while the world’s focus is elsewhere, and the nuclear community should continue to work together to progress nuclear non-proliferation and disarmament, building bridges of cooperation and trust that can long outlast the pandemic. Full Article
nuc {alpha}-Synuclein filaments from transgenic mouse and human synucleinopathy-containing brains are maȷor seed-competent species [Molecular Bases of Disease] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 Assembled α-synuclein in nerve cells and glial cells is the defining pathological feature of neurodegenerative diseases called synucleinopathies. Seeds of α-synuclein can induce the assembly of monomeric protein. Here, we used sucrose gradient centrifugation and transiently transfected HEK 293T cells to identify the species of α-synuclein from the brains of homozygous, symptomatic mice transgenic for human mutant A53T α-synuclein (line M83) that seed aggregation. The most potent fractions contained Sarkosyl-insoluble assemblies enriched in filaments. We also analyzed six cases of idiopathic Parkinson's disease (PD), one case of familial PD, and six cases of multiple system atrophy (MSA) for their ability to induce α-synuclein aggregation. The MSA samples were more potent than those of idiopathic PD in seeding aggregation. We found that following sucrose gradient centrifugation, the most seed-competent fractions from PD and MSA brains are those that contain Sarkosyl-insoluble α-synuclein. The fractions differed between PD and MSA, consistent with the presence of distinct conformers of assembled α-synuclein in these different samples. We conclude that α-synuclein filaments are the main driving force for amplification and propagation of pathology in synucleinopathies. Full Article
nuc Nuclear Tensions Must Not Be Sidelined During Coronavirus By feedproxy.google.com Published On :: Fri, 01 May 2020 11:18:35 +0000 1 May 2020 Ana Alecsandru Research Assistant, International Security Programme @anaalecs LinkedIn Although the pandemic means the Nuclear Non-Proliferation Treaty (NPT) Review Conference (RevCon) is postponed, the delay could be an opportunity to better the health of the NPT regime. 2020-05-01-Iran-Peace-Nuclear Painted stairs in Tehran, Iran symbolizing hope. Photo by Fatemeh Bahrami/Anadolu Agency/Getty Images. Despite face-to-face diplomatic meetings being increasingly rare during the current disruption, COVID-19 will ultimately force a redefinition of national security and defence spending priorities, and this could provide the possibility of an improved political climate at RevCon when it happens in 2021.With US presidential elections due in November and a gradual engagement growing between the EU and Iran, there could be a new context for more cooperation between states by 2021. Two key areas of focus over the coming months will be the arms control talks between the United States and Russia, and Iran’s compliance with the 2015 Joint Comprehensive Plan of Action (JCPOA), also known as the Iran Nuclear Deal.It is too early to discern the medium- and longer-term consequences of COVID-19 for defence ministries, but a greater focus on societal resilience and reinvigorating economic productivity will likely undercut the rationale for expensive nuclear modernization.Therefore, extending the current New START (Strategic Arms Reduction Treaty) would be the best, most practical option to give both Russia and the United States time to explore more ambitious multilateral arms control measures, while allowing their current focus to remain on the pandemic and economic relief.Continuing distrustBut with the current treaty — which limits nuclear warheads, missiles, bombers, and launchers — due to expire in February 2021, the continuing distrust between the United States and Russia makes this extension hard to achieve, and a follow-on treaty even less likely.Prospects for future bilateral negotiations are hindered by President Donald Trump’s vision for a trilateral arms control initiative involving both China and Russia. But China opposes this on the grounds that its nuclear arsenal is far smaller than that of the two others.While there appears to be agreement that the nuclear arsenals of China, France, and the UK (the NPT nuclear-weapons states) and those of the states outside the treaty (India, Pakistan, North Korea, and Israel) will all have to be taken into account going forward, a practical mechanism for doing so proves elusive.If Joe Biden wins the US presidency he seems likely to pursue an extension of the New START treaty and could also prevent a withdrawal from the Open Skies treaty, the latest arms control agreement targeted by the Trump administration.Under a Biden administration, the United States would also probably re-join the JCPOA, provided Tehran returned to strict compliance with the deal. Biden could even use the team that negotiated the Iran deal to advance the goal of denuclearization of the Korean peninsula.For an NPT regime already confronted by a series of longstanding divergences, it is essential that Iran remains a signatory especially as tensions between Iran and the United States have escalated recently — due to the Qassim Suleimani assassination and the recent claim by Iran’s Revolutionary Guard Corps to have successfully placed the country’s first military satellite into orbit.This announcement raised red flags among experts about whether Iran is developing intercontinental ballistic missiles due to the dual-use nature of space technology. The satellite launch — deeply troubling for Iran’s neighbours and the EU countries — may strengthen the US argument that it is a cover for the development of ballistic missiles capable of delivering nuclear weapons.However, as with many other countries, Iran is struggling with a severe coronavirus crisis and will be pouring its scientific expertise and funds into that rather than other efforts — including the nuclear programme.Those European countries supporting the trading mechanism INSTEX (Instrument in Support of Trade Exchanges) for sending humanitarian goods into Iran could use this crisis to encourage Iran to remain in compliance with the JCPOA and its NPT obligations.France, Germany and the UK (the E3) have already successfully concluded the first transaction, which was to facilitate the export of medical goods from Europe to Iran. But the recent Iranian escalatory steps will most certainly place a strain on the preservation of this arrangement.COVID-19 might have delayed Iran’s next breach of the 2015 nuclear agreement but Tehran will inevitably seek to strengthen its hand before any potential negotiations with the United States after the presidential elections.As frosty US-Iranian relations — exacerbated by the coronavirus pandemic — prevent diplomatic negotiations, this constructive engagement between the E3 and Iran might prove instrumental in reviving the JCPOA and ensuring Iran stays committed to both nuclear non-proliferation and disarmament.While countries focus their efforts on tackling the coronavirus pandemic, it is understandable resources may be limited for other global challenges, such as the increasing risk of nuclear weapons use across several regions.But the potential ramifications of the COVID-19 crisis for the NPT regime are profound. Ongoing tensions between the nuclear-armed states must not be ignored while the world’s focus is elsewhere, and the nuclear community should continue to work together to progress nuclear non-proliferation and disarmament, building bridges of cooperation and trust that can long outlast the pandemic. Full Article
nuc Talking to North Korea: Ending the Nuclear Standoff? By feedproxy.google.com Published On :: Tue, 09 Oct 2018 00:00:00 +0100 Full Article
nuc A Conversation With: Steven T Mnuchin, Secretary, US Treasury By feedproxy.google.com Published On :: Sat, 25 Jan 2020 00:00:00 +0000 Full Article
nuc Human Hepatocyte Nuclear Factor 4-{alpha} Encodes Isoforms with Distinct Transcriptional Functions [Research] By feedproxy.google.com Published On :: 2020-05-01T00:05:26-07:00 HNF4α is a nuclear receptor produced as 12 isoforms from two promoters by alternative splicing. To characterize the transcriptional capacities of all 12 HNF4α isoforms, stable lines expressing each isoform were generated. The entire transcriptome associated with each isoform was analyzed as well as their respective interacting proteome. Major differences were noted in the transcriptional function of these isoforms. The α1 and α2 isoforms were the strongest regulators of gene expression whereas the α3 isoform exhibited significantly reduced activity. The α4, α5, and α6 isoforms, which use an alternative first exon, were characterized for the first time, and showed a greatly reduced transcriptional potential with an inability to recognize the consensus response element of HNF4α. Several transcription factors and coregulators were identified as potential specific partners for certain HNF4α isoforms. An analysis integrating the vast amount of omics data enabled the identification of transcriptional regulatory mechanisms specific to certain HNF4α isoforms, hence demonstrating the importance of considering all isoforms given their seemingly diverse functions. Full Article
nuc Quantification of the affinities of CRISPR-Cas9 nucleases for cognate protospacer adȷacent motif (PAM) sequences [Molecular Biophysics] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 The CRISPR/Cas9 nucleases have been widely applied for genome editing in various organisms. Cas9 nucleases complexed with a guide RNA (Cas9–gRNA) find their targets by scanning and interrogating the genomic DNA for sequences complementary to the gRNA. Recognition of the DNA target sequence requires a short protospacer adjacent motif (PAM) located outside this sequence. Given that the efficiency of target location may depend on the strength of interactions that promote target recognition, here we sought to compare affinities of different Cas9 nucleases for their cognate PAM sequences. To this end, we measured affinities of Cas9 nucleases from Streptococcus pyogenes, Staphylococcus aureus, and Francisella novicida complexed with guide RNAs (gRNAs) (SpCas9–gRNA, SaCas9–gRNA, and FnCas9–gRNA, respectively) and of three engineered SpCas9–gRNA variants with altered PAM specificities for short, PAM-containing DNA probes. We used a “beacon” assay that measures the relative affinities of DNA probes by determining their ability to competitively affect the rate of Cas9–gRNA binding to fluorescently labeled target DNA derivatives called “Cas9 beacons.” We observed significant differences in the affinities for cognate PAM sequences among the studied Cas9 enzymes. The relative affinities of SpCas9–gRNA and its engineered variants for canonical and suboptimal PAMs correlated with previous findings on the efficiency of these PAM sequences in genome editing. These findings suggest that high affinity of a Cas9 nuclease for its cognate PAM promotes higher genome-editing efficiency. Full Article