PESHAWAR: Speaker Provincial Assembly Mushtaq Ahmed Ghani visited Khyber Teaching Hospital to take of situation with regard to coronavirus on Friday.He was received by Medical Director Prof Dr Aamir Azhar and the hospital’s media manager. The speaker was briefed by medical director on the...

PESHAWAR: Speaker Provincial Assembly Mushtaq Ahmed Ghani visited Khyber Teaching Hospital to take of situation with regard to coronavirus on Friday.He was received by Medical Director Prof Dr Aamir...

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Islamabad : President Arif Alvi on Friday directed that social distancing should be maintained in the upcoming session of the National Assembly for the safety of the parliamentarians and staff against the threat of coronavirus.During a visit to the National Assembly, the president was apprised by...

ABSTRACT

The translocation of effectors into the host cell through type 3 secretion systems (T3SS) is a sophisticated strategy employed by pathogenic bacteria to subvert host responses and facilitate colonization. Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) utilize the Tir and EspFu (also known as TccP) effectors to remodel the host cytoskeleton, culminating in the formation of attaching and effacing (AE) lesions on enterocytes. While some EPEC strains require tyrosine phosphorylation of Tir and recruitment of the host Nck to trigger actin polymerization, EHEC and certain EPEC strains, whose Tir is not phosphorylated, rely on the effector EspFu for efficient actin remodeling. Here, we investigated the role played by Tir-Nck and Tir-EspFu actin polymerization pathways during the infection of epithelial cells, as well as the host transcriptional response to the AE lesion formation induced by EPEC. We found that EspFu-mediated actin assembly promotes bacterial attachment and epithelial colonization more efficiently than Tir-Nck. Moreover, we showed that both actin polymerization mechanisms can activate inflammatory pathways and reverse the anti-inflammatory response induced by EPEC in epithelial cells. However, this activity is remarkably more evident in infections with EspFu-expressing EPEC strains. This study demonstrates the complex interactions between effector-mediated actin remodeling and inflammation. Different strains carry different combinations of these two effectors, highlighting the plasticity of pathogenic E. coli enteric infections.

IMPORTANCE EPEC is among the leading causes of diarrheal disease worldwide. The colonization of the gut mucosa by EPEC results in actin pedestal formation at the site of bacterial attachment. These pedestals are referred to as attaching and effacing (AE) lesions. Here, we exploit the different molecular mechanisms used by EPEC to induce AE lesions on epithelial cells, showing that the effector EspFu is associated with increased bacterial attachment and enhanced epithelial colonization compared to the Tir-Nck pathway. Moreover, we also showed that actin pedestal formation can counterbalance the anti-inflammatory activity induced by EPEC, especially when driven by EspFu. Collectively, our findings provide new insights into virulence mechanisms employed by EPEC to colonize epithelial cells, as well as the host response to this enteric pathogen.

The past decade has increased our understanding of how genome topology controls RAG endonuclease-mediated assembly of lymphocyte AgR genes. New technologies have illuminated how the large IgH, Ig, TCRα/, and TCRβ loci fold into compact structures that place their numerous V gene segments in similar three-dimensional proximity to their distal recombination center composed of RAG-bound (D)J gene segments. Many studies have shown that CTCF and cohesin protein–mediated chromosome looping have fundamental roles in lymphocyte lineage- and developmental stage–specific locus compaction as well as broad usage of V segments. CTCF/cohesin–dependent loops have also been shown to direct and restrict RAG activity within chromosome domains. We summarize recent work in elucidating molecular mechanisms that govern three-dimensional chromosome organization and in investigating how these dynamic mechanisms control V(D)J recombination. We also introduce remaining questions for how CTCF/cohesin–dependent and –independent genome architectural mechanisms might regulate compaction and recombination of AgR loci.

African swine fever (ASF) is a highly contagious hemorrhagic viral disease of domestic and wild pigs that is responsible for serious economic and production losses. It is caused by the African swine fever virus (ASFV), a large and complex icosahedral DNA virus of the Asfarviridae family. Currently, there is no effective treatment or approved vaccine against the ASFV. pS273R, a specific SUMO-1 cysteine protease, catalyzes the maturation of the pp220 and pp62 polyprotein precursors into core-shell proteins. Here, we present the crystal structure of the ASFV pS273R protease at a resolution of 2.3 Å. The overall structure of the pS273R protease is represented by two domains named the "core domain" and the N-terminal "arm domain." The "arm domain" contains the residues from M1 to N83, and the "core domain" contains the residues from N84 to A273. A structure analysis reveals that the "core domain" shares a high degree of structural similarity with chlamydial deubiquitinating enzyme, sentrin-specific protease, and adenovirus protease, while the "arm domain" is unique to ASFV. Further, experiments indicated that the "arm domain" plays an important role in maintaining the enzyme activity of ASFV pS273R. Moreover, based on the structural information of pS273R, we designed and synthesized several peptidomimetic aldehyde compounds at a submolar 50% inhibitory concentration, which paves the way for the design of inhibitors to target this severe pathogen.

IMPORTANCE African swine fever virus, a large and complex icosahedral DNA virus, causes a deadly infection in domestic pigs. In addition to Africa and Europe, countries in Asia, including China, Vietnam, and Mongolia, were negatively affected by the hazards posed by ASFV outbreaks in 2018 and 2019, at which time more than 30 million pigs were culled. Until now, there has been no vaccine for protection against ASFV infection or effective treatments to cure ASF. Here, we solved the high-resolution crystal structure of the ASFV pS273R protease. The pS273R protease has a two-domain structure that distinguishes it from other members of the SUMO protease family, while the unique "arm domain" has been proven to be essential for its hydrolytic activity. Moreover, the peptidomimetic aldehyde compounds designed to target the substrate binding pocket exert prominent inhibitory effects and can thus be used in a potential lead for anti-ASFV drug development.

G-quadruplex, assembled from a square array of guanine (G) molecules, is an important structure with crucial biological roles in vivo but also a versatile template for ordered functional materials. Although the understanding of G-quadruplex structures is the focus of numerous studies, little is known regarding the control of G-quartet stacking...

The outer segments (OS) of rod and cone photoreceptor cells are specialized sensory cilia that contain hundreds of opsin-loaded stacked membrane disks that enable phototransduction. The biogenesis of these disks is initiated at the OS base, but the driving force has been debated. Here, we studied the function of the...

Proteasomes are essential protease complexes that maintain cellular homeostasis, and aberrant proteasomal activity supports cancer development. The regulatory mechanisms and biological function of the ubiquitin-26S proteasome have been studied extensively, while those of the ubiquitin-independent 20S proteasome system remain obscure. Here, we show that the cap ’n’ collar (CNC) family transcription factor NRF3 specifically enhances 20S proteasome assembly in cancer cells and that 20S proteasomes contribute to colorectal cancer development through ubiquitin-independent proteolysis of the tumor suppressor p53 and retinoblastoma (Rb) proteins. The NRF3 gene is highly expressed in many cancer tissues and cell lines and is important for cancer cell growth. In cancer cells, NRF3 upregulates the assembly of the 20S proteasome by directly inducing the gene expression of the 20S proteasome maturation protein POMP. Interestingly, NRF3 knockdown not only increases p53 and Rb protein levels but also increases p53 activities for tumor suppression, including cell cycle arrest and induction of apoptosis. Furthermore, protein stability and cell viability assays using two distinct proteasome inhibitor anticancer drugs, the 20S proteasome inhibitor bortezomib and the ubiquitin-activating enzyme E1 inhibitor TAK-243, show that the upregulation of the NRF3-POMP axis leads to ubiquitin-independent proteolysis of p53 and Rb and to impaired sensitivity to bortezomib but not TAK-243. More importantly, the NRF3-POMP axis supports tumorigenesis and metastasis, with higher NRF3/POMP expression levels correlating with poor prognoses in patients with colorectal or rectal adenocarcinoma. These results suggest that the NRF3-POMP-20S proteasome assembly axis is significant for cancer development via ubiquitin-independent proteolysis of tumor suppressor proteins.

Lisa Müller, Katrin Rietscher, Rene Keil, Marvin Neuholz, and Mechthild Hatzfeld

Desmosome remodeling is crucial for epidermal regeneration, differentiation and wound healing. It is mediated by adapting the composition, and by post-translational modifications, of constituent proteins. We have previously demonstrated in mouse suprabasal keratinocytes that plakophilin (PKP) 1 mediates strong adhesion, which is negatively regulated by insulin-like growth factor 1 (IGF1) signaling. The importance of PKP3 for epidermal adhesion is incompletely understood. Here, we identify a major role of epidermal growth factor (EGF), but not IGF1, signaling in PKP3 recruitment to the plasma membrane to facilitate desmosome assembly. We find that ribosomal S6 kinases (RSKs) associate with and phosphorylate PKP3, which promotes PKP3 association with desmosomes downstream of the EGF receptor. Knockdown of RSKs as well as mutation of an RSK phosphorylation site in PKP3 interfered with desmosome formation, maturation and adhesion. Our findings implicate a coordinate action of distinct growth factors in the control of adhesive properties of desmosomes through modulation of PKPs in a context-dependent manner.

Kristi McElmurry, Jessica E. Stone, Donghan Ma, Phillip Lamoureux, Yueyun Zhang, Michelle Steidemann, Lucas Fix, Fang Huang, Kyle E. Miller, and Daniel M. Suter

Previously, we have shown that bulk microtubule (MT) movement correlates with neurite elongation, and blocking either dynein activity or MT assembly inhibits both processes. However, whether the contributions of MT dynamics and dynein activity to neurite elongation are separate or interdependent is unclear. Here, we investigated the underlying mechanism by testing the roles of dynein and MT assembly in neurite elongation of Aplysia and chick neurites using time-lapse imaging, fluorescent speckle microscopy, super-resolution imaging and biophysical analysis. Pharmacologically inhibiting either dynein activity or MT assembly reduced neurite elongation rates as well as bulk and individual MT anterograde translocation. Simultaneously suppressing both processes did not have additive effects, suggesting a shared mechanism of action. Single-molecule switching nanoscopy revealed that inhibition of MT assembly decreased the association of dynein with MTs. Finally, inhibiting MT assembly prevented the rise in tension induced by dynein inhibition. Taken together, our results suggest that MT assembly is required for dynein-driven MT translocation and neurite outgrowth.

Gastrointestinal (GI) or gut microbiotas play essential roles in host development and physiology. These roles are influenced partly by the microbial community composition. During early developmental stages, the ecological processes underlying the assembly and successional changes in host GI community composition are influenced by numerous factors, including dispersal from the surrounding environment, age-dependent changes in the gut environment, and changes in dietary regimes. However, the relative importance of these factors to the gut microbiota is not well understood. We examined the effects of environmental (diet and water sources) and host early ontogenetic development on the diversity of and the compositional changes in the gut microbiota of a primitive teleost fish, the lake sturgeon (Acipenser fulvescens), based on massively parallel sequencing of the 16S rRNA gene. Fish larvae were raised in environments that differed in water source (stream versus filtered groundwater) and diet (supplemented versus nonsupplemented Artemia fish). We quantified the gut microbial community structure at three stages (prefeeding and 1 and 2 weeks after exogenous feeding began). The diversity declined and the community composition differed significantly among stages; however, only modest differences associated with dietary or water source treatments were documented. Many taxa present in the gut were over- or underrepresented relative to neutral expectations in each sampling period. The findings indicate dynamic relationships between the gut microbiota composition and host gastrointestinal physiology, with comparatively smaller influences being associated with the rearing environments. Neutral models of community assembly could not be rejected, but selectivity associated with microbe-host GI tract interactions through early ontogenetic stages was evident. The results have implications for sturgeon conservation and aquaculture production specifically and applications of microbe-based management in teleost fish generally.

IMPORTANCE We quantified the effects of environment (diet and water sources) and host early ontogenetic development on the diversity of and compositional changes in gut microbial communities based on massively parallel sequencing of the 16S rRNA genes from the GI tracts of larval lake sturgeon (Acipenser fulvescens). The gut microbial community diversity declined and the community composition differed significantly among ontogenetic stages; however, only modest differences associated with dietary or water source treatments were documented. Selectivity associated with microbe-host GI tract interactions through early ontogenetic stages was evident. The results have implications for lake sturgeon and early larval ecology and survival in their natural habitat and for conservation and aquaculture production specifically, as well as applications of microbe-based management in teleost fish generally.

Capsid assembly is a critical step in the hepatitis B virus (HBV) life cycle, mediated by the core protein. Core is a potential target for new antiviral therapies, the capsid assembly modulators (CAMs). JNJ-56136379 (JNJ-6379) is a novel and potent CAM currently in phase II trials. We evaluated the mechanisms of action (MOAs) and antiviral properties of JNJ-6379 in vitro. Size exclusion chromatography and electron microscopy studies demonstrated that JNJ-6379 induced the formation of morphologically intact viral capsids devoid of genomic material (primary MOA). JNJ-6379 accelerated the rate and extent of HBV capsid assembly in vitro. JNJ-6379 specifically and potently inhibited HBV replication; its median 50% effective concentration (EC₅₀) was 54 nM (HepG2.117 cells). In HBV-infected primary human hepatocytes (PHHs), JNJ-6379, when added with the viral inoculum, dose-dependently reduced extracellular HBV DNA levels (median EC₅₀ of 93 nM) and prevented covalently closed circular DNA (cccDNA) formation, leading to a dose-dependent reduction of intracellular HBV RNA levels (median EC₅₀ of 876 nM) and reduced antigen levels (secondary MOA). Adding JNJ-6379 to PHHs 4 or 5 days postinfection reduced extracellular HBV DNA and did not prevent cccDNA formation. Time-of-addition PHH studies revealed that JNJ-6379 most likely interfered with postentry processes. Collectively, these data demonstrate that JNJ-6379 has dual MOAs in the early and late steps of the HBV life cycle, which is different from the MOA of nucleos(t)ide analogues. JNJ-6379 is in development for chronic hepatitis B treatment and may translate into higher HBV functional cure rates.

The Labor Party has walked out of the NSW Legislative Assembly after Opposition Leader Jody McKay is thrown out by the Speaker.

"Under the visionary leadership of Secretary General Noble, INTERPOL is already at the forefront of the battle against globalized crime. To highlight just one of the many critical steps he has taken: he has modernized the ‘I-24/7’ network, which is used thousands of times each day and millions of times each year to conduct the cross-border police work necessary to find and arrest wanted persons, and to solve and prevent crimes."

David Chui, a resident of Queens, N.Y., pleaded guilty to failing to pay employment taxes in connection with his former ownership of a garment assembly business.

"Over a decade ago, as a lawyer in the California Attorney General’s office, I worked on a variety of consumer protection issues, from identity theft to the victimization of elder consumers. And over the last three years, President Obama, Attorney General Eric Holder and I have made protecting consumers a centerpiece of the Justice Department’s overall anti-fraud efforts," said Acting Associate Attorney General West.

"I am here not only to pledge the United States’ commitment to these principles – but also our support for the United Nations’ robust efforts to strengthen the rule of law worldwide," said Attorney General Holder.

Since the beginning of the healthcare crisis, the decrees issued by the Conte government have, one after the other, increased the number of restrictions. This is on top of the ordinances from the different regions. A campaign has developed and has promoted social distancing through calls to stay at home, hashtags and appeals. But all this fervour did not affect the millions of workers forced to continue going to work in non-essential companies and services.

Delegates from United Nations member states meet to discuss a global environmental agenda.

In stark contrast to other flat-pack furniture designs, Groovebox is meant to be as simple to put together as possible, with no fasteners, tools, or mammoth assembly instructions needed.

The motion is non-binding, but that doesn't mean it doesn't matter.

As of 6 May, the name of Assembly Members will change to Members of the Senedd.

Three years on from the commitments made at the 2015 United Nations Climate Change Conference (COP21) in Paris, the overwhelming majority of governments have not taken the necessary action to contain growing risks to the climate, says the OECD. It said, with emissions on the rise again, OECD governments need to get serious about shifting their economies to a low-carbon model and stop investing in carbon-intensive infrastructure.

Several exit polls have predicted that Mamata Banerjee will return to power in the state

Of the 44 of the 294 constituencies, the Trinamool had forged ahead in 25

The Mamata Banerjee-led TMC is set for a monumental win in the state, brushing aside the challenge from a Congress-CPI(M) combine

Supporters gathered outside Mamata's house and chanted slogans like Thanda thanda cool, cool; ghore ghore Trinamool'

Despite the Narada sting and Saradha scam, the TMC government sailed through due to its laser-like focus on primary areas

The Congress-Left combine is ahead in 72 seats and BJP, in seven

BJP has finally achieved its objective of capturing power in Assam, a goal which it had been pursuing since the 1980s

West Bengal Congress chief Adhir Ranjan Chowdhury said that there were many reasons for the defeat and the party would review them

Chief Minister and party supremo Mamata Banerjee said that she will take oath on May 27

To read the results as a saffron surge or decimation of the Congress is to miss the big picture

Ajay Dey, who was previously elected from Santipur in Nadia district on Congress ticket, left the party to join Trinamool. But he was rejected by the voters this time

In this Assembly polls, BJP has not only garnered around 56 lakh votes, but has also made its presence felt in 262 out of 294 Assembly segments

While Kozhikode recorded 13.16% turnout till 9 a.m, it was 9.62% in Idukki and 8.21% in Thiruvananthapuram

Tight security has been put in place across the state with the deployment of about 52,000 police personnel from state police forces

CPI(M) leader V S Achuthanandan also asserted that his coalition was set to win the Kerala assembly election

Mammootty, his actor son Dulquar Salman and actor and BJP Rajya Sabha member Suresh Gopi were among the celebrities who cast their vote today

Earlier in the day, Prime Minister Narendra Modi urged voters in Tamil Nadu, Puducherry and Kerala to vote in record numbers

The state capital Thiruvananthapuram recorded the lowest of 44.93% till 3 pm

Kozhikode recorded the highest voting percentage at 81.89%

CPI(M) Polit Bureau member Prakash Karat said they do not generally go by the exit polls as they are "unreliable"

Ahead of counting of votes to decide political fate of five states, candidates were seen resorting to different means to calm their nerves Thursday morning

The two-month long campaign saw the ruling Congress-led UDF and CPI(M) headed LDF engaging in a fierce battle

According to Election officials, candidates from the Left Democratic Front (LDF) had forged ahead in 53 constituencies