chrome Chrome crashes, Edge works, major slowdown with PotPlayer By www.bleepingcomputer.com Published On :: 2020-05-08T11:23:20-05:00 Full Article
chrome Removing Chrome Extension Installed By Virus By www.bleepingcomputer.com Published On :: 2020-05-08T19:15:01-05:00 Full Article
chrome Need to wipe a Chromebook From Daughters School.. By www.bleepingcomputer.com Published On :: 2020-04-29T18:27:58-05:00 Full Article
chrome My Chrome Browser is not allowing me to access YouTube???? By www.bleepingcomputer.com Published On :: 2020-05-02T10:11:43-05:00 Full Article
chrome Conversion of 3-amino-4-arylamino-1H-isochromen-1-ones to 1-arylisochromeno[3,4-d][1,2,3]triazol-5(1H)-ones: synthesis, spectroscopic characterization and the structures of four products and one ring-opened derivative By scripts.iucr.org Published On :: 2020-04-20 An efficient synthesis of 1-arylisochromeno[3,4-d][1,2,3]triazol-5(1H)-ones, involving the diazotization of 3-amino-4-arylamino-1H-isochromen-1-ones in weakly acidic solution, has been developed and the spectroscopic characterization and crystal structures of four examples are reported. The molecules of 1-phenylisochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C15H9N3O2, (I), are linked into sheets by a combination of C—H⋯N and C—H⋯O hydrogen bonds, while the structures of 1-(2-methylphenyl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C16H11N3O2, (II), and 1-(3-chlorophenyl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C15H8ClN3O2, (III), each contain just one hydrogen bond which links the molecules into simple chains, which are further linked into sheets by π-stacking interactions in (II) but not in (III). In the structure of 1-(4-chlorophenyl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, (IV), isomeric with (III), a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds links the molecules into sheets. When compound (II) was exposed to a strong acid in methanol, quantitative conversion occurred to give the ring-opened transesterification product methyl 2-[4-hydroxy-1-(2-methylphenyl)-1H-1,2,3-triazol-5-yl]benzoate, C17H15N3O3, (V), where the molecules are linked by paired O—H⋯O hydrogen bonds to form centrosymmetric dimers. Full Article text
chrome Chromebook finds and displays gmail but no other web site By www.bleepingcomputer.com Published On :: 2019-02-27T18:00:34-05:00 Full Article
chrome Chromebook reset itself? By www.bleepingcomputer.com Published On :: 2019-03-24T06:21:52-05:00 Full Article
chrome Chromebook booting in developer mode? By www.bleepingcomputer.com Published On :: 2019-03-30T06:04:41-05:00 Full Article
chrome Chromebook charger blew fuse twice By www.bleepingcomputer.com Published On :: 2020-02-15T01:42:46-05:00 Full Article
chrome HP chromebook 15-de0000na 15.6" By www.bleepingcomputer.com Published On :: 2020-03-25T05:34:15-05:00 Full Article
chrome There is something very wrong with my chrome book! By www.bleepingcomputer.com Published On :: 2020-03-30T00:08:20-05:00 Full Article
chrome How to Install and Uninstall Google Chrome in Windows By www.bleepingcomputer.com Published On :: Thu, 05 Mar 2020 08:37:18 EST This tutorial will explain how to install or uninstall Google Chrome in Windows. [...] Full Article Tutorials How to Install and Uninstall Google Chrome in Windows
chrome How to Translate a Web Page in Google Chrome By www.bleepingcomputer.com Published On :: Mon, 09 Mar 2020 19:07:15 EDT The web is made up of terrific content from all over the world and sometimes the content you want to read is written in a different language. Thankfully, Google Chrome has built-in support for the Google Translate service, which will automatically translate the page into a language of your choice. [...] Full Article Tutorials How to Translate a Web Page in Google Chrome
chrome How to Open and Use the Google Chrome Task Manager By www.bleepingcomputer.com Published On :: 2017-09-19T12:50:05-05:00 Full Article
chrome How to determine why Google Chrome is using a lot of memory or CPU By www.bleepingcomputer.com Published On :: 2017-09-19T14:43:38-05:00 Full Article
chrome How to Reset The Chrome Browser To Its Default Settings By www.bleepingcomputer.com Published On :: 2018-03-16T15:33:58-05:00 Full Article
chrome How to Find the ID for a Chrome Extension By www.bleepingcomputer.com Published On :: 2019-01-14T09:27:18-05:00 Full Article
chrome My Chrome Browser is not allowing me to access YouTube???? By www.bleepingcomputer.com Published On :: 2020-05-02T10:11:43-05:00 Full Article
chrome How to start NetFlix in 'Puppy' direct from the Menu.....without opening Chrome By www.bleepingcomputer.com Published On :: 2017-11-10T15:05:21-05:00 Full Article
chrome Need to wipe a Chromebook From Daughters School.. By www.bleepingcomputer.com Published On :: 2020-04-29T18:27:58-05:00 Full Article
chrome Measuring Instrument Producer Anton Paar Acquires Quantachrome Instruments By www.24-7pressrelease.com Published On :: Mon, 12 Feb 2018 07:00:00 GMT Anton Paar, the world leader in measuring density, concentration, or dissolved CO2, has acquired Quantachrome which adds know-how in the analysis of particle surface areas, porosity and density of solids to the portfolio of 150+ analytical solutions. Full Article
chrome GiftWorksPlus Expands Line of Custom Frames to Include Chrome Collection By www.24-7pressrelease.com Published On :: Sat, 09 Mar 2013 07:00:00 GMT GiftWorksPlus is proud to introduce a new product line of custom picture frames: the chrome collection. Full Article
chrome 13 Amazing Free Chrome Extensions For SEO By feedproxy.google.com Published On :: Tue, 10 Mar 2020 12:44:00 +0000 Every SEO tool is different. Some have better keyword data, others have better link data, others give better technical suggestions… in other words, there is no perfect tool. And I really mean that, even though I created Ubersuggest for you. Plus paying for a handful of SEO tools can be expensive and isn’t realistic. But […] The post 13 Amazing Free Chrome Extensions For SEO appeared first on Neil Patel. Full Article SEO
chrome Interactive Marquee for Safari and Chrome By www.cssplay.co.uk Published On :: 2010-02-16 Using CSS3 and keyframes to produce an interactive marquee Full Article
chrome Interactive Marquee for Safari, Chrome and Firefox By www.cssplay.co.uk Published On :: 2012-05-14 A second version of the marquee demo using CSS3 and keyframes to produce an interactive marquee for any length of text. Full Article
chrome Three planets and the moon animation for Safari, Chrome and Firefox By www.cssplay.co.uk Published On :: 2012-05-21 Using CSS3 transitions, transforms and keyframes to produce a 3D animation of the Earth, Mars, Jupiter and the Moon. Full Article
chrome 3D Dymaxion Map animation for Safari, Chrome and Firefox By www.cssplay.co.uk Published On :: 2012-05-24 Using CSS3 transitions, transforms and keyframes to produce a 3D Dymaxion Map of the Earth's surface. Full Article
chrome Revolution Two: Chrome Theme By feedproxy.google.com Published On :: Sun, 03 May 2020 18:08:31 +0000 Benefits include the Chrome theme, unlimited theme support answered by our experts, customization techniques with our detailed theme tutorials and professional design services available by our list of recommended designers. The post Revolution Two: Chrome Theme appeared first on WPCult. Full Article Premium Premium Theme Revolution 2 Revolution Two: Chrome
chrome Monochrome beach By jepson.no Published On :: Wed, 13 Nov 2019 12:04:03 +0000 From Ølberg Strand. Taken with iPhone 11 Pro wide-angle and given some Lightroom fixes for sky effect. Full Article Blog
chrome 3-hydroxy-6H-benzo [C] chromene-6-one derivative and manufacturing method thereof By www.freepatentsonline.com Published On :: Tue, 12 May 2015 08:00:00 EDT A method of manufacturing a compound or a salt thereof expressed with a formula (III) below, characterized by causing a compound or a salt thereof expressed with a formula (I) below and a compound or a salt thereof expressed with a formula (II) below to react in the presence of carbonate and copper salt or in the presence of hydroxide salt, carbonate, and copper salt. Full Article
chrome Guessous v. Chrome Hearts, LLC By feeds.findlaw.com Published On :: 2009-12-01T08:00:00+00:00 (California Court of Appeal) - In plaintiff's suit against defendant for infringement of jewelry designs, trademarks and copyrights, trial court's decision denying plaintiff's motion to strike defendant's complaint under the anti-SLAPP statute is affirmed as the filing of a lawsuit in a foreign country is not protected activity under the United States or California Constitutions as to implicate the statute. Full Article Civil Procedure Contracts Copyright Intellectual Property Trade Dress Trademark
chrome Fake crypto-wallet extensions appear in Chrome Web Store once again, siphoning off victims' passwords By go.theregister.co.uk Published On :: Wed, 06 May 2020 20:55:29 GMT 'Seriously sometimes seems Google's moderators are only optimized to respond to social media outrage' Three weeks after Google removed 49 Chrome extensions from its browser's software store for stealing crypto-wallet credentials, 11 more password-swiping add-ons have been spotted – and some are still available to download.… Full Article
chrome Google Chrome rival gets vital features that could tempt you to make the switch By feedproxy.google.com Published On :: Sat, 09 May 2020 07:01:00 +0100 GOOGLE CHROME is the undisputed champion of the internet browser marketplace, but one of its big rivals has received a major update that may tempt you over. Full Article
chrome Spectral and photochemical diversity of tandem cysteine cyanobacterial phytochromes [Plant Biology] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 The atypical trichromatic cyanobacterial phytochrome NpTP1 from Nostoc punctiforme ATCC 29133 is a linear tetrapyrrole (bilin)-binding photoreceptor protein that possesses tandem-cysteine residues responsible for shifting its light-sensing maximum to the violet spectral region. Using bioinformatics and phylogenetic analyses, here we established that tandem-cysteine cyanobacterial phytochromes (TCCPs) compose a well-supported monophyletic phytochrome lineage distinct from prototypical red/far-red cyanobacterial phytochromes. To investigate the light-sensing diversity of this family, we compared the spectroscopic properties of NpTP1 (here renamed NpTCCP) with those of three phylogenetically diverged TCCPs identified in the draft genomes of Tolypothrix sp. PCC7910, Scytonema sp. PCC10023, and Gloeocapsa sp. PCC7513. Recombinant photosensory core modules of ToTCCP, ScTCCP, and GlTCCP exhibited violet-blue–absorbing dark-states consistent with dual thioether-linked phycocyanobilin (PCB) chromophores. Photoexcitation generated singly-linked photoproduct mixtures with variable ratios of yellow-orange and red-absorbing species. The photoproduct ratio was strongly influenced by pH and by mutagenesis of TCCP- and phytochrome-specific signature residues. Our experiments support the conclusion that both photoproduct species possess protonated 15E bilin chromophores, but differ in the ionization state of the noncanonical “second” cysteine sulfhydryl group. We found that the ionization state of this and other residues influences subsequent conformational change and downstream signal transmission. We also show that tandem-cysteine phytochromes present in eukaryotes possess similar amino acid substitutions within their chromophore-binding pocket, which tune their spectral properties in an analogous fashion. Taken together, our findings provide a roadmap for tailoring the wavelength specificity of plant phytochromes to optimize plant performance in diverse natural and artificial light environments. Full Article
chrome The cytochrome P450 enzyme CYP24A1 increases proliferation of mutant KRAS-dependent lung adenocarcinoma independent of its catalytic activity [Cell Biology] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 We previously reported that overexpression of cytochrome P450 family 24 subfamily A member 1 (CYP24A1) increases lung cancer cell proliferation by activating RAS signaling and that CYP24A1 knockdown inhibits tumor growth. However, the mechanism of CYP24A1-mediated cancer cell proliferation remains unclear. Here, we conducted cell synchronization and biochemical experiments in lung adenocarcinoma cells, revealing a link between CYP24A1 and anaphase-promoting complex (APC), a key cell cycle regulator. We demonstrate that CYP24A1 expression is cell cycle–dependent; it was higher in the G2-M phase and diminished upon G1 entry. CYP24A1 has a functional destruction box (D-box) motif that allows binding with two APC adaptors, CDC20-homologue 1 (CDH1) and cell division cycle 20 (CDC20). Unlike other APC substrates, however, CYP24A1 acted as a pseudo-substrate, inhibiting CDH1 activity and promoting mitotic progression. Conversely, overexpression of a CYP24A1 D-box mutant compromised CDH1 binding, allowing CDH1 hyperactivation, thereby hastening degradation of its substrates cyclin B1 and CDC20, and accumulation of the CDC20 substrate p21, prolonging mitotic exit. These activities also occurred with a CYP24A1 isoform 2 lacking the catalytic cysteine (Cys-462), suggesting that CYP24A1's oncogenic potential is independent of its catalytic activity. CYP24A1 degradation reduced clonogenic survival of mutant KRAS-driven lung cancer cells, and calcitriol treatment increased CYP24A1 levels and tumor burden in Lsl-KRASG12D mice. These results disclose a catalytic activity-independent growth-promoting role of CYP24A1 in mutant KRAS-driven lung cancer. This suggests that CYP24A1 could be therapeutically targeted in lung cancers in which its expression is high. Full Article
chrome Structure of an ancestral mammalian family 1B1 cytochrome P450 with increased thermostability [Enzymology] By feedproxy.google.com Published On :: 2020-04-24T06:08:45-07:00 Mammalian cytochrome P450 enzymes often metabolize many pharmaceuticals and other xenobiotics, a feature that is valuable in a biotechnology setting. However, extant P450 enzymes are typically relatively unstable, with T50 values of ∼30–40 °C. Reconstructed ancestral cytochrome P450 enzymes tend to have variable substrate selectivity compared with related extant forms, but they also have higher thermostability and therefore may be excellent tools for commercial biosynthesis of important intermediates, final drug molecules, or drug metabolites. The mammalian ancestor of the cytochrome P450 1B subfamily was herein characterized structurally and functionally, revealing differences from the extant human CYP1B1 in ligand binding, metabolism, and potential molecular contributors to its thermostability. Whereas extant human CYP1B1 has one molecule of α-naphthoflavone in a closed active site, we observed that subtle amino acid substitutions outside the active site in the ancestor CYP1B enzyme yielded an open active site with four ligand copies. A structure of the ancestor with 17β-estradiol revealed only one molecule in the active site, which still had the same open conformation. Detailed comparisons between the extant and ancestor forms revealed increases in electrostatic and aromatic interactions between distinct secondary structure elements in the ancestral forms that may contribute to their thermostability. To the best of our knowledge, this represents the first structural evaluation of a reconstructed ancestral cytochrome P450, revealing key features that appear to contribute to its thermostability. Full Article
chrome Spectral and photochemical diversity of tandem cysteine cyanobacterial phytochromes [Plant Biology] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 The atypical trichromatic cyanobacterial phytochrome NpTP1 from Nostoc punctiforme ATCC 29133 is a linear tetrapyrrole (bilin)-binding photoreceptor protein that possesses tandem-cysteine residues responsible for shifting its light-sensing maximum to the violet spectral region. Using bioinformatics and phylogenetic analyses, here we established that tandem-cysteine cyanobacterial phytochromes (TCCPs) compose a well-supported monophyletic phytochrome lineage distinct from prototypical red/far-red cyanobacterial phytochromes. To investigate the light-sensing diversity of this family, we compared the spectroscopic properties of NpTP1 (here renamed NpTCCP) with those of three phylogenetically diverged TCCPs identified in the draft genomes of Tolypothrix sp. PCC7910, Scytonema sp. PCC10023, and Gloeocapsa sp. PCC7513. Recombinant photosensory core modules of ToTCCP, ScTCCP, and GlTCCP exhibited violet-blue–absorbing dark-states consistent with dual thioether-linked phycocyanobilin (PCB) chromophores. Photoexcitation generated singly-linked photoproduct mixtures with variable ratios of yellow-orange and red-absorbing species. The photoproduct ratio was strongly influenced by pH and by mutagenesis of TCCP- and phytochrome-specific signature residues. Our experiments support the conclusion that both photoproduct species possess protonated 15E bilin chromophores, but differ in the ionization state of the noncanonical “second” cysteine sulfhydryl group. We found that the ionization state of this and other residues influences subsequent conformational change and downstream signal transmission. We also show that tandem-cysteine phytochromes present in eukaryotes possess similar amino acid substitutions within their chromophore-binding pocket, which tune their spectral properties in an analogous fashion. Taken together, our findings provide a roadmap for tailoring the wavelength specificity of plant phytochromes to optimize plant performance in diverse natural and artificial light environments. Full Article
chrome Cytochrome P450 and arachidonic acid bioactivation: molecular and functional properties of the arachidonate monooxygenase By feedproxy.google.com Published On :: 2000-02-01 Jorge H. CapdevilaFeb 1, 2000; 41:163-181Reviews Full Article
chrome X-ray structures of catalytic intermediates of cytochrome c oxidase provide insights into its O2 activation and unidirectional proton-pump mechanisms [Molecular Biophysics] By feedproxy.google.com Published On :: 2020-04-24T06:08:45-07:00 Cytochrome c oxidase (CcO) reduces O2 to water, coupled with a proton-pumping process. The structure of the O2-reduction site of CcO contains two reducing equivalents, Fea32+ and CuB1+, and suggests that a peroxide-bound state (Fea33+–O−–O−–CuB2+) rather than an O2-bound state (Fea32+–O2) is the initial catalytic intermediate. Unexpectedly, however, resonance Raman spectroscopy results have shown that the initial intermediate is Fea32+–O2, whereas Fea33+–O−–O−–CuB2+ is undetectable. Based on X-ray structures of static noncatalytic CcO forms and mutation analyses for bovine CcO, a proton-pumping mechanism has been proposed. It involves a proton-conducting pathway (the H-pathway) comprising a tandem hydrogen-bond network and a water channel located between the N- and P-side surfaces. However, a system for unidirectional proton-transport has not been experimentally identified. Here, an essentially identical X-ray structure for the two catalytic intermediates (P and F) of bovine CcO was determined at 1.8 Å resolution. A 1.70 Å Fe–O distance of the ferryl center could best be described as Fea34+ = O2−, not as Fea34+–OH−. The distance suggests an ∼800-cm−1 Raman stretching band. We found an interstitial water molecule that could trigger a rapid proton-coupled electron transfer from tyrosine-OH to the slowly forming Fea33+–O−–O−–CuB2+ state, preventing its detection, consistent with the unexpected Raman results. The H-pathway structures of both intermediates indicated that during proton-pumping from the hydrogen-bond network to the P-side, a transmembrane helix closes the water channel connecting the N-side with the hydrogen-bond network, facilitating unidirectional proton-pumping during the P-to-F transition. Full Article
chrome X-ray structures of catalytic intermediates of cytochrome c oxidase provide insights into its O2 activation and unidirectional proton-pump mechanisms [Molecular Biophysics] By feedproxy.google.com Published On :: 2020-04-24T06:08:45-07:00 Cytochrome c oxidase (CcO) reduces O2 to water, coupled with a proton-pumping process. The structure of the O2-reduction site of CcO contains two reducing equivalents, Fea32+ and CuB1+, and suggests that a peroxide-bound state (Fea33+–O−–O−–CuB2+) rather than an O2-bound state (Fea32+–O2) is the initial catalytic intermediate. Unexpectedly, however, resonance Raman spectroscopy results have shown that the initial intermediate is Fea32+–O2, whereas Fea33+–O−–O−–CuB2+ is undetectable. Based on X-ray structures of static noncatalytic CcO forms and mutation analyses for bovine CcO, a proton-pumping mechanism has been proposed. It involves a proton-conducting pathway (the H-pathway) comprising a tandem hydrogen-bond network and a water channel located between the N- and P-side surfaces. However, a system for unidirectional proton-transport has not been experimentally identified. Here, an essentially identical X-ray structure for the two catalytic intermediates (P and F) of bovine CcO was determined at 1.8 Å resolution. A 1.70 Å Fe–O distance of the ferryl center could best be described as Fea34+ = O2−, not as Fea34+–OH−. The distance suggests an ∼800-cm−1 Raman stretching band. We found an interstitial water molecule that could trigger a rapid proton-coupled electron transfer from tyrosine-OH to the slowly forming Fea33+–O−–O−–CuB2+ state, preventing its detection, consistent with the unexpected Raman results. The H-pathway structures of both intermediates indicated that during proton-pumping from the hydrogen-bond network to the P-side, a transmembrane helix closes the water channel connecting the N-side with the hydrogen-bond network, facilitating unidirectional proton-pumping during the P-to-F transition. Full Article
chrome More crypto-stealing Chrome extensions swatted by Google By feedproxy.google.com Published On :: Fri, 08 May 2020 10:15:05 +0000 Google deleted more malicious extensions from the Chrome Web Store after they were found to be phishing cryptocurrency users. Full Article Cryptocurrency Google Phishing Chrome extensions Chrome Web Store cryptocurrency wallet malicious extensions phishing
chrome X-ray structures of catalytic intermediates of cytochrome c oxidase provide insights into its O2 activation and unidirectional proton-pump mechanisms [Molecular Biophysics] By www.jbc.org Published On :: 2020-04-24T06:08:45-07:00 Cytochrome c oxidase (CcO) reduces O2 to water, coupled with a proton-pumping process. The structure of the O2-reduction site of CcO contains two reducing equivalents, Fea32+ and CuB1+, and suggests that a peroxide-bound state (Fea33+–O−–O−–CuB2+) rather than an O2-bound state (Fea32+–O2) is the initial catalytic intermediate. Unexpectedly, however, resonance Raman spectroscopy results have shown that the initial intermediate is Fea32+–O2, whereas Fea33+–O−–O−–CuB2+ is undetectable. Based on X-ray structures of static noncatalytic CcO forms and mutation analyses for bovine CcO, a proton-pumping mechanism has been proposed. It involves a proton-conducting pathway (the H-pathway) comprising a tandem hydrogen-bond network and a water channel located between the N- and P-side surfaces. However, a system for unidirectional proton-transport has not been experimentally identified. Here, an essentially identical X-ray structure for the two catalytic intermediates (P and F) of bovine CcO was determined at 1.8 Å resolution. A 1.70 Å Fe–O distance of the ferryl center could best be described as Fea34+ = O2−, not as Fea34+–OH−. The distance suggests an ∼800-cm−1 Raman stretching band. We found an interstitial water molecule that could trigger a rapid proton-coupled electron transfer from tyrosine-OH to the slowly forming Fea33+–O−–O−–CuB2+ state, preventing its detection, consistent with the unexpected Raman results. The H-pathway structures of both intermediates indicated that during proton-pumping from the hydrogen-bond network to the P-side, a transmembrane helix closes the water channel connecting the N-side with the hydrogen-bond network, facilitating unidirectional proton-pumping during the P-to-F transition. Full Article
chrome Structure of an ancestral mammalian family 1B1 cytochrome P450 with increased thermostability [Enzymology] By www.jbc.org Published On :: 2020-04-24T06:08:45-07:00 Mammalian cytochrome P450 enzymes often metabolize many pharmaceuticals and other xenobiotics, a feature that is valuable in a biotechnology setting. However, extant P450 enzymes are typically relatively unstable, with T50 values of ∼30–40 °C. Reconstructed ancestral cytochrome P450 enzymes tend to have variable substrate selectivity compared with related extant forms, but they also have higher thermostability and therefore may be excellent tools for commercial biosynthesis of important intermediates, final drug molecules, or drug metabolites. The mammalian ancestor of the cytochrome P450 1B subfamily was herein characterized structurally and functionally, revealing differences from the extant human CYP1B1 in ligand binding, metabolism, and potential molecular contributors to its thermostability. Whereas extant human CYP1B1 has one molecule of α-naphthoflavone in a closed active site, we observed that subtle amino acid substitutions outside the active site in the ancestor CYP1B enzyme yielded an open active site with four ligand copies. A structure of the ancestor with 17β-estradiol revealed only one molecule in the active site, which still had the same open conformation. Detailed comparisons between the extant and ancestor forms revealed increases in electrostatic and aromatic interactions between distinct secondary structure elements in the ancestral forms that may contribute to their thermostability. To the best of our knowledge, this represents the first structural evaluation of a reconstructed ancestral cytochrome P450, revealing key features that appear to contribute to its thermostability. Full Article
chrome The cytochrome P450 enzyme CYP24A1 increases proliferation of mutant KRAS-dependent lung adenocarcinoma independent of its catalytic activity [Cell Biology] By www.jbc.org Published On :: 2020-05-01T00:06:09-07:00 We previously reported that overexpression of cytochrome P450 family 24 subfamily A member 1 (CYP24A1) increases lung cancer cell proliferation by activating RAS signaling and that CYP24A1 knockdown inhibits tumor growth. However, the mechanism of CYP24A1-mediated cancer cell proliferation remains unclear. Here, we conducted cell synchronization and biochemical experiments in lung adenocarcinoma cells, revealing a link between CYP24A1 and anaphase-promoting complex (APC), a key cell cycle regulator. We demonstrate that CYP24A1 expression is cell cycle–dependent; it was higher in the G2-M phase and diminished upon G1 entry. CYP24A1 has a functional destruction box (D-box) motif that allows binding with two APC adaptors, CDC20-homologue 1 (CDH1) and cell division cycle 20 (CDC20). Unlike other APC substrates, however, CYP24A1 acted as a pseudo-substrate, inhibiting CDH1 activity and promoting mitotic progression. Conversely, overexpression of a CYP24A1 D-box mutant compromised CDH1 binding, allowing CDH1 hyperactivation, thereby hastening degradation of its substrates cyclin B1 and CDC20, and accumulation of the CDC20 substrate p21, prolonging mitotic exit. These activities also occurred with a CYP24A1 isoform 2 lacking the catalytic cysteine (Cys-462), suggesting that CYP24A1's oncogenic potential is independent of its catalytic activity. CYP24A1 degradation reduced clonogenic survival of mutant KRAS-driven lung cancer cells, and calcitriol treatment increased CYP24A1 levels and tumor burden in Lsl-KRASG12D mice. These results disclose a catalytic activity-independent growth-promoting role of CYP24A1 in mutant KRAS-driven lung cancer. This suggests that CYP24A1 could be therapeutically targeted in lung cancers in which its expression is high. Full Article
chrome The cytochrome P450 enzyme CYP24A1 increases proliferation of mutant KRAS-dependent lung adenocarcinoma independent of its catalytic activity [Cell Biology] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 We previously reported that overexpression of cytochrome P450 family 24 subfamily A member 1 (CYP24A1) increases lung cancer cell proliferation by activating RAS signaling and that CYP24A1 knockdown inhibits tumor growth. However, the mechanism of CYP24A1-mediated cancer cell proliferation remains unclear. Here, we conducted cell synchronization and biochemical experiments in lung adenocarcinoma cells, revealing a link between CYP24A1 and anaphase-promoting complex (APC), a key cell cycle regulator. We demonstrate that CYP24A1 expression is cell cycle–dependent; it was higher in the G2-M phase and diminished upon G1 entry. CYP24A1 has a functional destruction box (D-box) motif that allows binding with two APC adaptors, CDC20-homologue 1 (CDH1) and cell division cycle 20 (CDC20). Unlike other APC substrates, however, CYP24A1 acted as a pseudo-substrate, inhibiting CDH1 activity and promoting mitotic progression. Conversely, overexpression of a CYP24A1 D-box mutant compromised CDH1 binding, allowing CDH1 hyperactivation, thereby hastening degradation of its substrates cyclin B1 and CDC20, and accumulation of the CDC20 substrate p21, prolonging mitotic exit. These activities also occurred with a CYP24A1 isoform 2 lacking the catalytic cysteine (Cys-462), suggesting that CYP24A1's oncogenic potential is independent of its catalytic activity. CYP24A1 degradation reduced clonogenic survival of mutant KRAS-driven lung cancer cells, and calcitriol treatment increased CYP24A1 levels and tumor burden in Lsl-KRASG12D mice. These results disclose a catalytic activity-independent growth-promoting role of CYP24A1 in mutant KRAS-driven lung cancer. This suggests that CYP24A1 could be therapeutically targeted in lung cancers in which its expression is high. Full Article
chrome Structure of an ancestral mammalian family 1B1 cytochrome P450 with increased thermostability [Enzymology] By feedproxy.google.com Published On :: 2020-04-24T06:08:45-07:00 Mammalian cytochrome P450 enzymes often metabolize many pharmaceuticals and other xenobiotics, a feature that is valuable in a biotechnology setting. However, extant P450 enzymes are typically relatively unstable, with T50 values of ∼30–40 °C. Reconstructed ancestral cytochrome P450 enzymes tend to have variable substrate selectivity compared with related extant forms, but they also have higher thermostability and therefore may be excellent tools for commercial biosynthesis of important intermediates, final drug molecules, or drug metabolites. The mammalian ancestor of the cytochrome P450 1B subfamily was herein characterized structurally and functionally, revealing differences from the extant human CYP1B1 in ligand binding, metabolism, and potential molecular contributors to its thermostability. Whereas extant human CYP1B1 has one molecule of α-naphthoflavone in a closed active site, we observed that subtle amino acid substitutions outside the active site in the ancestor CYP1B enzyme yielded an open active site with four ligand copies. A structure of the ancestor with 17β-estradiol revealed only one molecule in the active site, which still had the same open conformation. Detailed comparisons between the extant and ancestor forms revealed increases in electrostatic and aromatic interactions between distinct secondary structure elements in the ancestral forms that may contribute to their thermostability. To the best of our knowledge, this represents the first structural evaluation of a reconstructed ancestral cytochrome P450, revealing key features that appear to contribute to its thermostability. Full Article
chrome Coronavirus Squeezes Supply of Chromebooks, iPads, and Other Digital Learning Devices By feedproxy.google.com Published On :: Wed, 01 Apr 2020 00:00:00 +0000 School districts are competing against each other for purchases of digital devices as remote learning expands to schools across the country. Full Article Massachusetts
chrome Bad Flaw in Windows 10 Also Affects Chrome Browser By www.pcmag.com Published On :: Security researchers are demonstrating how you can use the Windows 10 flaw, CVE-2020-0601, to spoof the trusted digital certificates for official website domains on Google's Chrome browser. These same certificates can warn you about hacking attempts. Full Article
chrome The Best Chromebooks for 2020 By www.pcmag.com Published On :: Budget-friendly, web-centric Chromebooks can save you money. But is it worth opting for one if you can find a capable Windows 10 laptop for well under $500? Here's what you need to know, along with the best Chromebook models we have tested. Full Article
chrome Google Duo to allow users to make video calls on Chrome By feedproxy.google.com Published On :: 2020-05-09T19:20:16+05:30 Full Article Apps