a ‘DOG-EAT-DOG’ TIME IN D’CUP - A15 /// MANNING CUP CHAMPIONS READY TO SHIFT GEAR - A18 By jamaica-star.com Published On :: Fri, 08 Nov 2024 05:01:19 -0500 PROMOTED RACING, CHAPELTON MAROONS RENEW RIVALRY IN JPL - A16 FUNCAANDUN SET FOR FIFTH STRAIGHT WIN - A21 Full Article
a D’Yani eager for upcoming UK tour By jamaica-star.com Published On :: Fri, 08 Nov 2024 05:00:51 -0500 Reggae crooner D'Yani has exclaimed surprise at the momentum building up for his upcoming United Kingdom (UK) tour. "I'm still in shock that the early bird tickets were sold out so quickly, " he told THE WEEKEND STAR. D'Yani, born Andre... Full Article
a ‘My Ting Different’ - Tosh Alexander blends R&B and dancehall on new single By jamaica-star.com Published On :: Fri, 08 Nov 2024 05:01:03 -0500 Dynamic singer Tosh Alexander has been lighting up the music scene with her latest track, ' My Ting Different', a thrilling collaboration with American rapper and songwriter Lady London. The song fuses R... Full Article
a Scammers posing as Nigy Boy’s team trick promoter By jamaica-star.com Published On :: Fri, 08 Nov 2024 05:01:12 -0500 Nigy Boy's management team was forced to put out a scam alert on Thursday as news surfaced that a promoter in the Turks and Caicos Islands, inadvertently wired thousands of US dollars to who he believed was the artiste's booking team as a deposit... Full Article
a Vybz Kartel, Shenseea nominated for Best Reggae Album Grammy By jamaica-star.com Published On :: Fri, 08 Nov 2024 12:04:07 -0500 Full Article
a Cali P enjoys buzz with ‘Secret Hater’ By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:03 -0500 Switzerland-based reggae and dancehall recording artiste Cali P has expressed gratitude to the public for supporting his music, following the release of his latest single ' Secret Hater'. The song, which was produced jointly by himself and Suku... Full Article
a ENTERTAINMENT DIARY By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:12 -0500 TODAY KINGSTON... Full Article
a 50,000 bulbs to sparkle Rockefeller Christmas tree By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:13 -0500 NEW YORK (AP): The Rockefeller Center Christmas tree arrived in New York City on Saturday, signalling the start of the holiday season in the Big Apple. The 74-foot Norway spruce was driven into Manhattan's Center Plaza, where it was hoisted in... Full Article
a Beyoncé makes Grammy history By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:15 -0500 NEW YORK (AP): When it comes to the 2025 Grammy Award nominations, Cowboy Carter rules. Its superstar singer, Beyonce, leads the nods with 11, bringing her career total to 99 nominations. That makes her the most nominated artiste in Grammy history... Full Article
a ‘One-burner’ life - Vybz Kartel credits fiancée for new chapter By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:17 -0500 Long hailed as dancehall's most controversial figure, Vybz Kartel has always commanded the spotlight with his edgy lyrics and unfiltered persona. But since his release from prison in July, Kartel has begun to show a surprising transformation that'... Full Article
a Black Fyah rising above painful mishap By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:00:51 -0500 When a scuba diver comes up from the deep too quickly, the rapid decrease in pressure can give them a case of "the bends" or decompression sickness. It is caused by bubbles of gas building up in the body, causing pain. It can also be fatal.... Full Article
a Shocking Murray looks to Africa By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:00:54 -0500 Reggae artiste and TikToker Shocking Murray says he is both eager and excited about the prospect of touring Africa early next year to promote his recently released EP, Unchained. "I'll never forget the first time I toured Africa; it was in 2022... Full Article
a Jah Kettle wraps up successful tour By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:00:55 -0500 Reggae artiste Jah Kettle says he was pleased with his recently concluded Canada tour and is now excited to release a new single, titled Nothing Gonna Take Your Love Away, done with fellow reggae act Ras Penco. "The fans were riveting and showed... Full Article
a Dubbi gaining traction with ‘Side Chick’ By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:00:56 -0500 UK-based, Jamaica-born dancehall artiste Dubbi believes latest single, ' Side Chick' is a bona fide hit as its popularity has surged on the dancehall scene in the United Kingdom. "It is also streaming well in France and seems to be a real hit on... Full Article
a ENTERTAINMENT DIARY By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:00:58 -0500 TODAY KINGSTON... Full Article
a Recall was electric By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:00:59 -0500 Mas Camp on Arthur Wint Drive in St Andrew was transformed into a retro paradise last weekend as Recall, a retro party, took fans on a journey back to the golden days of dancehall. The 'Print Pink' theme was in full effect, and the ladies were... Full Article
a Near-death experience inspires Benzly Hype’s album By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:01:17 -0500 An out-of-body experience is the inspiration behind Benzly Hype's latest album Star Its The 7th Year. Released on November 7, the entertainer said the project was done to bring back joy in music and will leave its listeners in an upbeat mood.... Full Article
a Genetic diseases of the Kennedy pathways for membrane synthesis [Molecular Bases of Disease] By www.jbc.org Published On :: 2020-12-18T00:06:18-08:00 The two branches of the Kennedy pathways (CDP-choline and CDP-ethanolamine) are the predominant pathways responsible for the synthesis of the most abundant phospholipids, phosphatidylcholine and phosphatidylethanolamine, respectively, in mammalian membranes. Recently, hereditary diseases associated with single gene mutations in the Kennedy pathways have been identified. Interestingly, genetic diseases within the same pathway vary greatly, ranging from muscular dystrophy to spastic paraplegia to a childhood blinding disorder to bone deformations. Indeed, different point mutations in the same gene (PCYT1; CCTα) result in at least three distinct diseases. In this review, we will summarize and review the genetic diseases associated with mutations in genes of the Kennedy pathway for phospholipid synthesis. These single-gene disorders provide insight, indeed direct genotype-phenotype relationships, into the biological functions of specific enzymes of the Kennedy pathway. We discuss potential mechanisms of how mutations within the same pathway can cause disparate disease. Full Article
a ‘We have lost a future scientist’ - William Knibb High student gets emotional send-off By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:16 -0500 Family, friends, and community members gathered on Saturday at the Falmouth First Assembly Church to celebrate the life of 15-year-old Jahmarie Reid, a William Knibb High student who tragically lost his life at sea on August 27 in what is believed... Full Article
a A mom’s worst nightmare - East Kingston mother mourns teen son after deadly clash with cops By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:19 -0500 Kadian Morgan was overwhelmed with grief as she leaned against a wall outside her gate on Jackson Lane, East Kingston, yesterday, tears streaming down her face. Her 19-year-old son, Kayshan 'Bem Bem' Smith, was lying in the morgue after being... Full Article
a Making the dead look better - Jamaican morticians get advanced skills in embalming and cosmetics By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:27 -0500 For many Jamaicans, the deceased are more than just loved ones who have passed on; they are cherished family members who deserve to look as presentable as they did in life. In a culture where the appearance of the deceased is paramount, morticians... Full Article
a Childhood rape survivor earns university degree By jamaica-star.com Published On :: Mon, 11 Nov 2024 05:01:23 -0500 Earlier this month when Alicea Samaru-Brown walked across the stage at The University of the West Indies (UWI) graduation, she beamed with pride. Her husband, Dennis Brown, and her son, Orlando Brown, cheered the loudest from the audience and this... Full Article
a Fisherman shot and killed in Old Harbour Bay By jamaica-star.com Published On :: Mon, 11 Nov 2024 11:00:46 -0500 The St Catherine South police are probing the fatal shooting of a fisherman in Old Harbour Bay in the parish on Sunday. Full Article
a Policeman's murder won't deter fight against crime says Superintendent Nicholson By jamaica-star.com Published On :: Mon, 11 Nov 2024 12:52:26 -0500 A police sergeant who was shot and injured at his home in Portmore, St Catherine, on Thursday night succumbed to his injuries on Monday morning. Full Article
a Police make arrest relating to bags of cash that allegedly fell from Beryllium vehicle By jamaica-star.com Published On :: Mon, 11 Nov 2024 15:41:35 -0500 The police have arrested an individual in the probe surrounding two bags of cash that allegedly fell from a Beryllium security vehicle en route to the Norman Manley International Airport in Kingston last week. Full Article
a ‘Dead has no power’ - Mortician speaks on faith and ‘spirits’ in the funeral home By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:00:57 -0500 As I walked into the embalming room at Jones Funeral Home and Supplies in Kingston on Sunday, I immediately felt the weight of the room. The air was thick with the scent of various chemicals used in the trade permeating the space. Tools such as... Full Article
a Ganja use playing role in motor vehicle crashes By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:01:02 -0500 A growing number of motor vehicle crashes across Jamaica has been attributed to drivers operating the vehicles under the influence of marijuana, according to Health Minister Dr Christopher Tufton. "The data is clear, we are seeing more people... Full Article
a Vaping sending youth to hospital By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:01:04 -0500 Health Minister Dr Christopher Tufton is warning about the possible dangers to the health of students caused by vaping. "We have seen cases where students have been rushed to the A... Full Article
a Bridge over troubled water - Bushy Park residents construct new walkway after floodwaters sweep away old one By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:01:10 -0500 After parking his taxi cab along the sidewalk, Leon Thompson exited his vehicle and held on tightly to the tiny hands of his four small passengers. They all walked towards a makeshift bridge, and Thompson lifted each child, making four trips,... Full Article
a St Thomas residents plan proper funeral for Donovan By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:01:08 -0500 In a touching display of compassion and solidarity, a group of St Thomas residents has come together to organise the funeral of a a well-known and beloved man with intellectual challenges. For years, Donovan Sinclair was a familiar face in the... Full Article
a Man leaving home to live in cemetery By jamaica-star.com Published On :: Tue, 12 Nov 2024 05:01:12 -0500 With tears streaming down his face and his voice trembling, a windshield wiper made a declaration that he would rather live in the cemetery than with his relatives. "A the cemetery me ago live. Unnu wicked to me," Ramarieo Bailey declared. Bailey... Full Article
a Manchester man charged with smoking ganja in public By jamaica-star.com Published On :: Tue, 12 Nov 2024 10:09:40 -0500 Twenty-eight-year-old labourer Michael Ennis, of Manning's Hill district in Manchester, has been charged with smoking ganja in a public place following an incident in May Pen, Clarendon on Monday. Full Article
a Haiti's main airport and capital frozen after a day of violence By jamaica-star.com Published On :: Tue, 12 Nov 2024 12:00:31 -0500 PORT-AU-PRINCE, Haiti (AP) — Haiti's main airport remained closed on Tuesday, a day after violence erupted as the country swore in its new prime minister in a politically tumultuous transition. Full Article
a Workers at the Secrets and Breathless resorts protest overwork and low wages By jamaica-star.com Published On :: Tue, 12 Nov 2024 12:55:26 -0500 Staff at the Secrets and Breathless resorts in Montego Bay, St James, walked off the job this morning complaining of overwork, low wages, lack of overtime pay and disrespect. Full Article
a Landscaper charged for allegedly stealing oranges By jamaica-star.com Published On :: Tue, 12 Nov 2024 10:02:45 -0500 The Clarendon police have arrested and charged 25-year-old landscaper Anthony Marshall, of Lamparth district, Trout Hall in the parish for allegedly stealing oranges from a property in his community on Sunday. Full Article
a Father imprisoned for sexually molesting daughter By jamaica-star.com Published On :: Tue, 12 Nov 2024 14:54:04 -0500 A father who pleaded guilty to sexually molesting his 13-year-old daughter was sentenced to several years of imprisonment in the St Catherine Circuit Court on Tuesday. Full Article
a SAS Notes for SAS®9 - 66562: Negative values appear for distinct counts in SAS Visual Analytics reports By Published On :: Wed, 2 Sep 2020 12:58:12 EST When using the distinct count function in SAS Visual Analytics reports, you might find that a negative value is displayed instead of the actual distinct count: imgalt="distinct_count" src="{fusion_66562_1_disti Full Article VISANLYTBNDL+SAS+Visual+Analytics
a SAS Notes for SAS®9 - 66492: FILENAME FTP(FTP/TLS) fails with "ERROR: The connection was reset by a peer" due to using implicit FTP/TLS By Published On :: Wed, 26 Aug 2020 13:59:34 EST If you connect to a FTP/TLS server that is configured to use implicit FTP/TLS, FILENAME FTP/TLS might fail with the following error: ERRO Full Article BASE+Base+SAS
a A trade-off switch of two immunological memories in Caenorhabditis elegans reinfected by bacterial pathogens [Microbiology] By www.jbc.org Published On :: 2020-12-11T00:06:21-08:00 Recent studies have suggested that innate immune responses exhibit characteristics associated with memory linked to modulations in both vertebrates and invertebrates. However, the diverse evolutionary paths taken, particularly within the invertebrate taxa, should lead to similarly diverse innate immunity memory processes. Our understanding of innate immune memory in invertebrates primarily comes from studies of the fruit fly Drosophila melanogaster, the generality of which is unclear. Caenorhabditis elegans typically inhabits soil harboring a variety of fatal microbial pathogens; for this invertebrate, the innate immune system and aversive behavior are the major defensive strategies against microbial infection. However, their characteristics of immunological memory remains infantile. Here we discovered an immunological memory that promoted avoidance and suppressed innate immunity during reinfection with bacteria, which we revealed to be specific to the previously exposed pathogens. During this trade-off switch of avoidance and innate immunity, the chemosensory neurons AWB and ADF modulated production of serotonin and dopamine, which in turn decreased expression of the innate immunity-associated genes and led to enhanced avoidance via the downstream insulin-like pathway. Therefore, our current study profiles the immune memories during C. elegans reinfected by pathogenic bacteria and further reveals that the chemosensory neurons, the neurotransmitter(s), and their associated molecular signaling pathways are responsible for a trade-off switch between the two immunological memories. Full Article
a Biochemical transformation of bacterial lipopolysaccharides by acyloxyacyl hydrolase reduces host injury and promotes recovery [Enzymology] By www.jbc.org Published On :: 2020-12-18T00:06:18-08:00 Animals can sense the presence of microbes in their tissues and mobilize their own defenses by recognizing and responding to conserved microbial structures (often called microbe-associated molecular patterns (MAMPs)). Successful host defenses may kill the invaders, yet the host animal may fail to restore homeostasis if the stimulatory microbial structures are not silenced. Although mice have many mechanisms for limiting their responses to lipopolysaccharide (LPS), a major Gram-negative bacterial MAMP, a highly conserved host lipase is required to extinguish LPS sensing in tissues and restore homeostasis. We review recent progress in understanding how this enzyme, acyloxyacyl hydrolase (AOAH), transforms LPS from stimulus to inhibitor, reduces tissue injury and death from infection, prevents prolonged post-infection immunosuppression, and keeps stimulatory LPS from entering the bloodstream. We also discuss how AOAH may increase sensitivity to pulmonary allergens. Better appreciation of how host enzymes modify LPS and other MAMPs may help prevent tissue injury and hasten recovery from infection. Full Article
a Mouse Ifit1b is a cap1-RNA-binding protein that inhibits mouse coronavirus translation and is regulated by complexing with Ifit1c [RNA] By www.jbc.org Published On :: 2020-12-18T00:06:18-08:00 Knockout mouse models have been extensively used to study the antiviral activity of IFIT (interferon-induced protein with tetratricopeptide repeats). Human IFIT1 binds to cap0 (m7GpppN) RNA, which lacks methylation on the first and second cap-proximal nucleotides (cap1, m7GpppNm, and cap2, m7GpppNmNm, respectively). These modifications are signatures of “self” in higher eukaryotes, whereas unmodified cap0-RNA is recognized as foreign and, therefore, potentially harmful to the host cell. IFIT1 inhibits translation at the initiation stage by competing with the cap-binding initiation factor complex, eIF4F, restricting infection by certain viruses that possess “nonself” cap0-mRNAs. However, in mice and other rodents, the IFIT1 orthologue has been lost, and the closely related Ifit1b has been duplicated twice, yielding three paralogues: Ifit1, Ifit1b, and Ifit1c. Although murine Ifit1 is similar to human IFIT1 in its cap0-RNA–binding selectivity, the roles of Ifit1b and Ifit1c are unknown. Here, we found that Ifit1b preferentially binds to cap1-RNA, whereas binding is much weaker to cap0- and cap2-RNA. In murine cells, we show that Ifit1b can modulate host translation and restrict WT mouse coronavirus infection. We found that Ifit1c acts as a stimulatory cofactor for both Ifit1 and Ifit1b, promoting their translation inhibition. In this way, Ifit1c acts in an analogous fashion to human IFIT3, which is a cofactor to human IFIT1. This work clarifies similarities and differences between the human and murine IFIT families to facilitate better design and interpretation of mouse models of human infection and sheds light on the evolutionary plasticity of the IFIT family. Full Article
a Development of a novel mammalian display system for selection of antibodies against membrane proteins [Immunology] By www.jbc.org Published On :: 2020-12-25T00:06:31-08:00 Reliable, specific polyclonal and monoclonal antibodies are important tools in research and medicine. However, the discovery of antibodies against their targets in their native forms is difficult. Here, we present a novel method for discovery of antibodies against membrane proteins in their native configuration in mammalian cells. The method involves the co-expression of an antibody library in a population of mammalian cells that express the target polypeptide within a natural membrane environment on the cell surface. Cells that secrete a single-chain fragment variable (scFv) that binds to the target membrane protein thereby become self-labeled, enabling enrichment and isolation by magnetic sorting and FRET-based flow sorting. Library sizes of up to 109 variants can be screened, thus allowing campaigns of naïve scFv libraries to be selected against membrane protein antigens in a Chinese hamster ovary cell system. We validate this method by screening a synthetic naïve human scFv library against Chinese hamster ovary cells expressing the oncogenic target epithelial cell adhesion molecule and identify a panel of three novel binders to this membrane protein, one with a dissociation constant (KD) as low as 0.8 nm. We further demonstrate that the identified antibodies have utility for killing epithelial cell adhesion molecule–positive cells when used as a targeting domain on chimeric antigen receptor T cells. Thus, we provide a new tool for identifying novel antibodies that act against membrane proteins, which could catalyze the discovery of new candidates for antibody-based therapies. Full Article
a C-tag TNF: a reporter system to study TNF shedding [Methods and Resources] By www.jbc.org Published On :: 2020-12-25T00:06:30-08:00 TNF is a highly pro-inflammatory cytokine that contributes not only to the regulation of immune responses but also to the development of severe inflammatory diseases. TNF is synthesized as a transmembrane protein, which is further matured via proteolytic cleavage by metalloproteases such as ADAM17, a process known as shedding. At present, TNF is mainly detected by measuring the precursor or the mature cytokine of bulk cell populations by techniques such as ELISA or immunoblotting. However, these methods do not provide information on the exact timing and extent of TNF cleavage at single-cell resolution and they do not allow the live visualization of shedding events. Here, we generated C-tag TNF as a genetically encoded reporter to study TNF shedding at the single-cell level. The functionality of the C-tag TNF reporter is based on the exposure of a cryptic epitope on the C terminus of the transmembrane portion of pro-TNF on cleavage. In both denatured and nondenatured samples, this epitope can be detected by a nanobody in a highly sensitive and specific manner only upon TNF shedding. As such, C-tag TNF can successfully be used for the detection of TNF cleavage in flow cytometry and live-cell imaging applications. We furthermore demonstrate its applicability in a forward genetic screen geared toward the identification of genetic regulators of TNF maturation. In summary, the C-tag TNF reporter can be employed to gain novel insights into the complex regulation of ADAM-dependent TNF shedding. Full Article
a Quantitative phosphoproteomic analysis reveals involvement of PD-1 in multiple T cell functions [Signal Transduction] By www.jbc.org Published On :: 2020-12-25T00:06:30-08:00 Programmed cell death protein 1 (PD-1) is a critical inhibitory receptor that limits excessive T cell responses. Cancer cells have evolved to evade these immunoregulatory mechanisms by upregulating PD-1 ligands and preventing T cell–mediated anti-tumor responses. Consequently, therapeutic blockade of PD-1 enhances T cell–mediated anti-tumor immunity, but many patients do not respond and a significant proportion develop inflammatory toxicities. To improve anti-cancer therapy, it is critical to reveal the mechanisms by which PD-1 regulates T cell responses. We performed global quantitative phosphoproteomic interrogation of PD-1 signaling in T cells. By complementing our analysis with functional validation assays, we show that PD-1 targets tyrosine phosphosites that mediate proximal T cell receptor signaling, cytoskeletal organization, and immune synapse formation. PD-1 ligation also led to differential phosphorylation of serine and threonine sites within proteins regulating T cell activation, gene expression, and protein translation. In silico predictions revealed that kinase/substrate relationships engaged downstream of PD-1 ligation. These insights uncover the phosphoproteomic landscape of PD-1–triggered pathways and reveal novel PD-1 substrates that modulate diverse T cell functions and may serve as future therapeutic targets. These data are a useful resource in the design of future PD-1–targeting therapeutic approaches. Full Article
a Carnosine synthase deficiency is compatible with normal skeletal muscle and olfactory function but causes reduced olfactory sensitivity in aging mice [Developmental Biology] By www.jbc.org Published On :: 2020-12-11T00:06:20-08:00 Carnosine (β-alanyl-l-histidine) and anserine (β-alanyl-3-methyl-l-histidine) are abundant peptides in the nervous system and skeletal muscle of many vertebrates. Many in vitro and in vivo studies demonstrated that exogenously added carnosine can improve muscle contraction, has antioxidant activity, and can quench various reactive aldehydes. Some of these functions likely contribute to the proposed anti-aging activity of carnosine. However, the physiological role of carnosine and related histidine-containing dipeptides (HCDs) is not clear. In this study, we generated a mouse line deficient in carnosine synthase (Carns1). HCDs were undetectable in the primary olfactory system and skeletal muscle of Carns1-deficient mice. Skeletal muscle contraction in these mice, however, was unaltered, and there was no evidence for reduced pH-buffering capacity in the skeletal muscle. Olfactory tests did not reveal any deterioration in 8-month-old mice lacking carnosine. In contrast, aging (18–24-month-old) Carns1-deficient mice exhibited olfactory sensitivity impairments that correlated with an age-dependent reduction in the number of olfactory receptor neurons. Whereas we found no evidence for elevated levels of lipoxidation and glycation end products in the primary olfactory system, protein carbonylation was increased in the olfactory bulb of aged Carns1-deficient mice. Taken together, these results suggest that carnosine in the olfactory system is not essential for information processing in the olfactory signaling pathway but does have a role in the long-term protection of olfactory receptor neurons, possibly through its antioxidant activity. Full Article
a ARID4B is critical for mouse embryonic stem cell differentiation towards mesoderm and endoderm, linking epigenetics to pluripotency exit [Developmental Biology] By www.jbc.org Published On :: 2020-12-18T00:06:18-08:00 Distinct cell types emerge from embryonic stem cells through a precise and coordinated execution of gene expression programs during lineage commitment. This is established by the action of lineage specific transcription factors along with chromatin complexes. Numerous studies have focused on epigenetic factors that affect embryonic stem cells (ESC) self-renewal and pluripotency. However, the contribution of chromatin to lineage decisions at the exit from pluripotency has not been as extensively studied. Using a pooled epigenetic shRNA screen strategy, we identified chromatin-related factors critical for differentiation toward mesodermal and endodermal lineages. Here we reveal a critical role for the chromatin protein, ARID4B. Arid4b-deficient mESCs are similar to WT mESCs in the expression of pluripotency factors and their self-renewal. However, ARID4B loss results in defects in up-regulation of the meso/endodermal gene expression program. It was previously shown that Arid4b resides in a complex with SIN3A and HDACS 1 and 2. We identified a physical and functional interaction of ARID4B with HDAC1 rather than HDAC2, suggesting functionally distinct Sin3a subcomplexes might regulate cell fate decisions Finally, we observed that ARID4B deficiency leads to increased H3K27me3 and a reduced H3K27Ac level in key developmental gene loci, whereas a subset of genomic regions gain H3K27Ac marks. Our results demonstrate that epigenetic control through ARID4B plays a key role in the execution of lineage-specific gene expression programs at pluripotency exit. Full Article
a Importance of endothelial Hey1 expression for thoracic great vessel development and its distal enhancer for Notch-dependent endothelial transcription [Gene Regulation] By www.jbc.org Published On :: 2020-12-18T00:06:18-08:00 Thoracic great vessels such as the aorta and subclavian arteries are formed through dynamic remodeling of embryonic pharyngeal arch arteries (PAAs). Previous work has shown that loss of a basic helix-loop-helix transcription factor Hey1 in mice causes abnormal fourth PAA development and lethal great vessel anomalies resembling congenital malformations in humans. However, how Hey1 mediates vascular formation remains unclear. In this study, we revealed that Hey1 in vascular endothelial cells, but not in smooth muscle cells, played essential roles for PAA development and great vessel morphogenesis in mouse embryos. Tek-Cre–mediated Hey1 deletion in endothelial cells affected endothelial tube formation and smooth muscle differentiation in embryonic fourth PAAs and resulted in interruption of the aortic arch and other great vessel malformations. Cell specificity and signal responsiveness of Hey1 expression were controlled through multiple cis-regulatory regions. We found two distal genomic regions that had enhancer activity in endothelial cells and in the pharyngeal epithelium and somites, respectively. The novel endothelial enhancer was conserved across species and was specific to large-caliber arteries. Its transcriptional activity was regulated by Notch signaling in vitro and in vivo, but not by ALK1 signaling and other transcription factors implicated in endothelial cell specificity. The distal endothelial enhancer was not essential for basal Hey1 expression in mouse embryos but may likely serve for Notch-dependent transcriptional control in endothelial cells together with the proximal regulatory region. These findings help in understanding the significance and regulation of endothelial Hey1 as a mediator of multiple signaling pathways in embryonic vascular formation. Full Article
a Peptidoglycan analysis reveals that synergistic deacetylase activity in vegetative Clostridium difficile impacts the host response [Glycobiology and Extracellular Matrices] By www.jbc.org Published On :: 2020-12-04T00:06:06-08:00 Clostridium difficile is an anaerobic and spore-forming bacterium responsible for 15–25% of postantibiotic diarrhea and 95% of pseudomembranous colitis. Peptidoglycan is a crucial element of the bacterial cell wall that is exposed to the host, making it an important target for the innate immune system. The C. difficile peptidoglycan is largely N-deacetylated on its glucosamine (93% of muropeptides) through the activity of enzymes known as N-deacetylases, and this N-deacetylation modulates host–pathogen interactions, such as resistance to the bacteriolytic activity of lysozyme, virulence, and host innate immune responses. C. difficile genome analysis showed that 12 genes potentially encode N-deacetylases; however, which of these N-deacetylases are involved in peptidoglycan N-deacetylation remains unknown. Here, we report the enzymes responsible for peptidoglycan N-deacetylation and their respective regulation. Through peptidoglycan analysis of several mutants, we found that the N-deacetylases PdaV and PgdA act in synergy. Together they are responsible for the high level of peptidoglycan N-deacetylation in C. difficile and the consequent resistance to lysozyme. We also characterized a third enzyme, PgdB, as a glucosamine N-deacetylase. However, its impact on N-deacetylation and lysozyme resistance is limited, and its physiological role remains to be dissected. Finally, given the influence of peptidoglycan N-deacetylation on host defense against pathogens, we investigated the virulence and colonization ability of the mutants. Unlike what has been shown in other pathogenic bacteria, a lack of N-deacetylation in C. difficile is not linked to a decrease in virulence. Full Article
a Fluctuation in O-GlcNAcylation inactivates STIM1 to reduce store-operated calcium ion entry via down-regulation of Ser621 phosphorylation [Molecular Bases of Disease] By www.jbc.org Published On :: 2020-12-11T00:06:20-08:00 Stromal interaction molecule 1 (STIM1) plays a pivotal role in store-operated Ca2+ entry (SOCE), an essential mechanism in cellular calcium signaling and in maintaining cellular calcium balance. Because O-GlcNAcylation plays pivotal roles in various cellular function, we examined the effect of fluctuation in STIM1 O-GlcNAcylation on SOCE activity. We found that both increase and decrease in STIM1 O-GlcNAcylation impaired SOCE activity. To determine the molecular basis, we established STIM1-knockout HEK293 (STIM1-KO-HEK) cells using the CRISPR/Cas9 system and transfected STIM1 WT (STIM1-KO-WT-HEK), S621A (STIM1-KO-S621A-HEK), or T626A (STIM1-KO-T626A-HEK) cells. Using these cells, we examined the possible O-GlcNAcylation sites of STIM1 to determine whether the sites were O-GlcNAcylated. Co-immunoprecipitation analysis revealed that Ser621 and Thr626 were O-GlcNAcylated and that Thr626 was O-GlcNAcylated in the steady state but Ser621 was not. The SOCE activity in STIM1-KO-S621A-HEK and STIM1-KO-T626A-HEK cells was lower than that in STIM1-KO-WT-HEK cells because of reduced phosphorylation at Ser621. Treatment with the O-GlcNAcase inhibitor Thiamet G or O-GlcNAc transferase (OGT) transfection, which increases O-GlcNAcylation, reduced SOCE activity, whereas treatment with the OGT inhibitor ST045849 or siOGT transfection, which decreases O-GlcNAcylation, also reduced SOCE activity. Decrease in SOCE activity due to increase and decrease in O-GlcNAcylation was attributable to reduced phosphorylation at Ser621. These data suggest that both decrease in O-GlcNAcylation at Thr626 and increase in O-GlcNAcylation at Ser621 in STIM1 lead to impairment of SOCE activity through decrease in Ser621 phosphorylation. Targeting STIM1 O-GlcNAcylation could provide a promising treatment option for the related diseases, such as neurodegenerative diseases. Full Article
a N-acetylglucosamine drives myelination by triggering oligodendrocyte precursor cell differentiation [Molecular Bases of Disease] By www.jbc.org Published On :: 2020-12-18T00:06:18-08:00 Myelination plays an important role in cognitive development and in demyelinating diseases like multiple sclerosis (MS), where failure of remyelination promotes permanent neuro-axonal damage. Modification of cell surface receptors with branched N-glycans coordinates cell growth and differentiation by controlling glycoprotein clustering, signaling, and endocytosis. GlcNAc is a rate-limiting metabolite for N-glycan branching. Here we report that GlcNAc and N-glycan branching trigger oligodendrogenesis from precursor cells by inhibiting platelet-derived growth factor receptor-α cell endocytosis. Supplying oral GlcNAc to lactating mice drives primary myelination in newborn pups via secretion in breast milk, whereas genetically blocking N-glycan branching markedly inhibits primary myelination. In adult mice with toxin (cuprizone)-induced demyelination, oral GlcNAc prevents neuro-axonal damage by driving myelin repair. In MS patients, endogenous serum GlcNAc levels inversely correlated with imaging measures of demyelination and microstructural damage. Our data identify N-glycan branching and GlcNAc as critical regulators of primary myelination and myelin repair and suggest that oral GlcNAc may be neuroprotective in demyelinating diseases like MS. Full Article