Journal of Biological Chemistry最新文献_第9页

Structural and functional analysis of Pseudomonas aeruginosa PelA provides insight into the modification of the Pel exopolysaccharide. 铜绿假单胞菌PelA的结构和功能分析为Pel外多糖的修饰提供了新的思路。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-20 DOI: 10.1016/j.jbc.2025.108432

Jaime C Van Loon, François Le Mauff, Mario A Vargas, Stephanie Gilbert, Roland Pfoh, Zachary A Morrison, Erum Razvi, Mark Nitz, Donald C Sheppard, P Lynne Howell

{"title":"Structural and functional analysis of Pseudomonas aeruginosa PelA provides insight into the modification of the Pel exopolysaccharide.","authors":"Jaime C Van Loon, François Le Mauff, Mario A Vargas, Stephanie Gilbert, Roland Pfoh, Zachary A Morrison, Erum Razvi, Mark Nitz, Donald C Sheppard, P Lynne Howell","doi":"10.1016/j.jbc.2025.108432","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108432","url":null,"abstract":"A major biofilm matrix determinant of Pseudomonas aeruginosa is the partially deacetylated α-1,4 linked N-acetylgalactosamine polymer, Pel. After synthesis and transport of the GalNAc polysaccharide across the inner membrane, PelA partially deacetylates and hydrolyzes Pel before its export out of the cell via PelB. While the Pel modification and export proteins are known to interact in the periplasm, it is unclear how the interaction of PelA and PelB coordinates these processes. To determine how PelA modifies the polymer, we determined its structure to 2.1 Å and found a unique arrangement of four distinct domains. We have shown previously that the hydrolase domain exhibits endo-α-1,4-N-acetylgalactosaminidase activity. Characterization of the deacetylase domain revealed that PelA is the founding member of a new carbohydrate esterase family, CE#. Further, we found that the PelAB interaction enhances the deacetylation of N-acetylgalactosamine oligosaccharides. Using the PelA structure in conjunction with AlphaFold2 modelling of the PelAB complex, we propose a model wherein PelB guides Pel to the deacetylase domain of PelA and subsequently to the porin domain of PelB for export. Perturbation or loss of the PelAB interaction would result in less efficient deacetylation and potentially increase Pel hydrolysis. In PelA homologues across many phyla, the predicted structure and active sites are conserved, suggesting a common modification mechanism in Gram-negative bacterial species containing a functional pel operon.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108432"},"PeriodicalIF":4.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Hippo pathway effector YAP inhibits NF-κB signaling and ccRCC growth by opposing ZHX2. Hippo通路效应物YAP通过对抗ZHX2抑制NF-κB信号和ccRCC生长。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-20 DOI: 10.1016/j.jbc.2025.108430

Xu Li, Yong Suk Cho, Yuhong Han, Mengmeng Zhou, Yuchen Liu, Yingzi Yang, Shu Zhuo, Jin Jiang

{"title":"The Hippo pathway effector YAP inhibits NF-κB signaling and ccRCC growth by opposing ZHX2.","authors":"Xu Li, Yong Suk Cho, Yuhong Han, Mengmeng Zhou, Yuchen Liu, Yingzi Yang, Shu Zhuo, Jin Jiang","doi":"10.1016/j.jbc.2025.108430","DOIUrl":"10.1016/j.jbc.2025.108430","url":null,"abstract":"The prevailing view in the cancer field is that Hippo signaling pathway functions as a tumor suppressor pathway by blocking the oncogenic potential of the pathway effectors Yes1 associated transcriptional regulator (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ). However, YAP can also function as a context-dependent tumor suppressor in several types of cancer including clear cell renal cell carcinomas (ccRCC). We find that, in additional to inhibiting hypoxia-inducible factor 2α (HIF2α), a major oncogenic driver in Von Hippel-Lindau (VHL)-/- ccRCC, YAP also blocks nuclear factor κB (NF-κB) signaling in ccRCC to inhibit cancer cell growth under conditions where HIF2α is dispensable. Mechanistically, YAP inhibits the expression of Zinc fingers and homeoboxes 2 (ZHX2), a VHL substrate and critical co-factor of NF-κB in ccRCC. Furthermore, YAP competes with ZHX2 for binding to the NF-κB subunit p65. Consequently, elevated nuclear YAP blocks the cooperativity between ZHX2 and the NF-κB subunit p65, leading to diminished NF-κB target gene expression. Pharmacological inhibition of Hippo kinase blocked NF-κB transcriptional program and suppressed ccRCC cancer cell growth, which can be rescued by overexpression of ZHX2 or p65. Our study uncovers a crosstalk between the Hippo and NF-κB/ZHX2 pathways and its involvement in ccRCC growth inhibition, suggesting that targeting the Hippo pathway may provide a therapeutical opportunity for ccRCC treatment.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108430"},"PeriodicalIF":4.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dissecting RNA selectivity mediated by tandem RNA-binding domains. 串联RNA结合域介导的解剖RNA选择性。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-20 DOI: 10.1016/j.jbc.2025.108435

Sarah E Harris, Yue Hu, Kaitlin Bridges, Francisco F Cavazos, Justin G Martyr, Bryan B Guzmán, Jernej Murn, Maria M Aleman, Daniel Dominguez

{"title":"Dissecting RNA selectivity mediated by tandem RNA-binding domains.","authors":"Sarah E Harris, Yue Hu, Kaitlin Bridges, Francisco F Cavazos, Justin G Martyr, Bryan B Guzmán, Jernej Murn, Maria M Aleman, Daniel Dominguez","doi":"10.1016/j.jbc.2025.108435","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108435","url":null,"abstract":"RNA-protein interactions are pivotal to proper gene regulation. Many RNA-binding proteins possess multiple RNA-binding domains; however, how these domains interplay to select and regulate RNA targets remains poorly understood. Here, we investigate three multi-domain proteins, Musashi-1, Musashi-2, and unkempt, which share a high degree of RNA specificity, a common feature across RNA-binding proteins. We used massively parallel in vitro assays with unprecedented depth with random or naturally-derived RNA sequences and find that individual domains within a protein can have differing affinities, specificities, and motif spacing preferences. We conducted large scale competition assays between these proteins and determined how individual protein specificities and affinities influence competitive binding. Integration of binding and regulation in cells with in vitro specificities showed that target selection involves a combination of the protein intrinsic specificities described here, but cellular context is critical to drive these proteins to motifs in specific transcript regions. Finally, evolutionarily conserved RNA regions displayed evidence of binding multiple RBPs in cultured cells, and these RNA regions represent the highest affinity targets. This work emphasizes the importance of in vitro and in cultured cells studies to fully profile RNA-binding proteins and highlights the complex modes of RNA-protein interactions and the contributing factors in target selection.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108435"},"PeriodicalIF":4.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Epitomic Profiling and Functional Characteristics of Pemphigus Vulgaris Autoantibody Binding to Keratinocyte M3 Muscarinic Acetylcholine Receptor. 寻常型天疱疮自身抗体结合角质细胞M3毒蕈碱乙酰胆碱受体的表位特征及功能特征。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-20 DOI: 10.1016/j.jbc.2025.108434

Jorge Mauricio Reyes-Ruiz, Alex Chernyavsky, Sergei A Grando, Charles Glabe

{"title":"Epitomic Profiling and Functional Characteristics of Pemphigus Vulgaris Autoantibody Binding to Keratinocyte M3 Muscarinic Acetylcholine Receptor.","authors":"Jorge Mauricio Reyes-Ruiz, Alex Chernyavsky, Sergei A Grando, Charles Glabe","doi":"10.1016/j.jbc.2025.108434","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108434","url":null,"abstract":"Patients with pemphigus vulgaris (PV) develop IgG autoantibodies (AuAbs) binding to keratinocyte desmogleins (Dsg), acetylcholine (ACh) receptors, mitochondrial proteins, and some other self-antigens. In this study, we identified linear and discontinuous peptide tetrameric epitope segments (ES) of M3 muscarinic ACh receptor (M3AR) targeted by different anti-M3AR AuAbs. As positive controls, we identified Dsg1 and Dsg3 ES targeted by PV sera. Healthy individuals also possessed natural antibodies targeting M3AR, Dsg1 and Dsg3 epitopes that were different from those targeted by AuAbs produced by PV patients. The two targeted M3AR pentameric ES encompass the 10 amino acids-long epitope LSEPTITFGT included the tetramer TFGT containing Thr235 which is a part of the ACh-binding pocket. Previously, it has been demonstrated that the anti-M3AR AuAb produces an agonist-like effect on downstream signaling, but its long-term effect is receptor desensitization. In this study, we compared the functional consequences of binding anti-M3AR AuAbs that target the ACh-binding pocket with that of AuAbs that target M3AR outside of its ACh-binding pocket. While the former AuAbs induced a very high elevation of phospholipase C, inositol triphosphate and diacylglycerol, which represents an agonist-like effect, the latter AuAbs produced a much weaker signaling response. These results indicate that PV patients develop two types of anti-M3AR AuAbs. One type attaches to orthosteric, ie, ACh-binding, site and elicits a strong signaling response comparable to that induced by a full pharmacologic agonist, whereas another type binds to an allosteric site and elicits submaximal signaling response comparable to that induced by a partial (allosteric) agonist.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108434"},"PeriodicalIF":4.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evolutionary duplication of the leishmanial adaptor protein α-SNAP plays a role in its pathogenicity. 利什曼适应蛋白α-SNAP的进化复制在其致病性中起作用。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-19 DOI: 10.1016/j.jbc.2025.108427

Shankari Prasad Datta, Chinmoy Sankar Dey

{"title":"Evolutionary duplication of the leishmanial adaptor protein α-SNAP plays a role in its pathogenicity.","authors":"Shankari Prasad Datta, Chinmoy Sankar Dey","doi":"10.1016/j.jbc.2025.108427","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108427","url":null,"abstract":"Essential-gene duplication during evolution promotes specialized functions beyond the typical role. Our in-silico study unveiled two α-SNAP paralogs in Leishmania, a crucial component that, along with NSF, triggers disassembly of the cis-SNARE complex, formed during vesicle fusion with target membranes. While multiple α-SNAPs are common in many flagellated protists, including the trypanosomatids, they are unusual among other eukaryotes. This study explores the evolutionary and functional relevance of α-SNAP gene duplication in Leishmania donovani, emphasizing both subfunctionalization and neofunctionalization. We discovered that Leishmania donovani α-SNAP (Ldα-SNAP) genes are transcribed in promastigote and amastigote stages, indicating they are not pseudogenes. Although the two paralogs share essential residues and structural features, only Ldα-SNAP1660 (Ldα-SNAP1) can effectively substitute the function of its yeast counterpart, while Ldα-SNAP3040 (Ldα-SNAP2) cannot. This functional difference is attributed to a replacement of alanine with phosphorylatable-serine in Ldα-SNAP1 during evolution from the most common ancestral ortholog. This modification is rarely observed in corresponding orthologs of other trypanosomatids. Incidentally, Ldα-SNAP paralogs exhibit differential localization in the ER and flagellar pocket. However, both paralogs, either actively or passively, regulate the secretion of exosomes and PM blebs, containing the virulence protein GP63. This indicates functional division and their indirect participation in host's macrophage inactivation. Moreover, a small fraction of Ldα-SNAP1's presence in flagellum hints at a potential role in sensing environmental cues and aiding parasite's attachment to the sandfly's hindgut. Our findings underscore that duplicated Ldα-SNAPs have retained ancestral functions through subfunctionalization, and subsequently, they acquired parasite-specific neofunction(s) through accumulation of natural mutation(s).","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108427"},"PeriodicalIF":4.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143674025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A combination of alveolar type 2-specific p38α activation with a high-fat diet increases inflammatory markers in mouse lungs. 肺泡2型特异性p38α激活与高脂肪饮食的结合增加了小鼠肺部的炎症标志物。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-19 DOI: 10.1016/j.jbc.2025.108425

C K Matthew Heng, Ilona Darlyuk-Saadon, Wupeng Liao, Manju P Mohanam, Phyllis X L Gan, Nechama Gilad, Christabel C M Y Chan, Inbar Plaschkes, W S Fred Wong, David Engelberg

{"title":"A combination of alveolar type 2-specific p38α activation with a high-fat diet increases inflammatory markers in mouse lungs.","authors":"C K Matthew Heng, Ilona Darlyuk-Saadon, Wupeng Liao, Manju P Mohanam, Phyllis X L Gan, Nechama Gilad, Christabel C M Y Chan, Inbar Plaschkes, W S Fred Wong, David Engelberg","doi":"10.1016/j.jbc.2025.108425","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108425","url":null,"abstract":"Chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD) afflict millions of individuals globally and are significant sources of disease mortality. While the molecular mechanisms underlying such diseases are unclear, environmental and social factors, such as cigarette smoke and obesity, increase the risk of disease development. Yet not all smokers or obese individuals will develop chronic respiratory diseases. The MAPK p38α is abnormally active in such maladies, but its contribution, if any, to disease aetiology is unknown. To assess whether p38α activation per se in the lung could impose disease symptoms, we generated a transgenic mouse model allowing controllable expression of an intrinsically active variant, p38αD176A+F327S, specifically in lung alveolar type 2 (AT2) pneumocytes. Sustained expression of p38αD176A+F327S did not appear to induce obvious pathological outcomes or to exacerbate inflammatory outcomes in mice challenged with common respiratory disease triggers. However, mice expressing p38αD176A+F327S in AT2 cells and fed with a high-fat diet (HFD) exhibited increased numbers of airway eosinophils and lymphocytes, upregulated levels of pro-inflammatory cytokines and chemokines including interleukin-1β and eotaxin, as well as a reduction in levels of leptin and adiponectin within the lung. Neither HFD nor p38αD176A+F327S alone induced such outcomes. Perhaps in obese individuals with associated respiratory diseases, elevated p38α activity which happens to occur is the factor that promotes their development.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108425"},"PeriodicalIF":4.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143673964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamics of β-cardiac myosin between the super-relaxed and disordered-relaxed states. β-心肌肌球蛋白在超放松和无序放松状态之间的动态变化。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-19 DOI: 10.1016/j.jbc.2025.108412

Robert C Cail, Faviolla A Baez-Cruz, Donald A Winkelmann, Yale E Goldman, E Michael Ostap

引用次数: 0

Polarization-independent regulation of the subcellular localization of Yes-associated protein 1 during preimplantation development. 胚胎着床前发育过程中yes相关蛋白1亚细胞定位的极化不依赖调控。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-19 DOI: 10.1016/j.jbc.2025.108429

Shun Saito, Koji Nishiyama, Hanako Bai, Masashi Takahashi, Manabu Kawahara

{"title":"Polarization-independent regulation of the subcellular localization of Yes-associated protein 1 during preimplantation development.","authors":"Shun Saito, Koji Nishiyama, Hanako Bai, Masashi Takahashi, Manabu Kawahara","doi":"10.1016/j.jbc.2025.108429","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108429","url":null,"abstract":"Cell polarization is a crucial developmental process that determines cell differentiation in mouse embryos. During this process, an extensively expressed transcriptional regulator, Yes-associated protein 1 (YAP1), is localized either to the cytoplasm or nucleus via HIPPO signaling. In mouse pre-morula embryos, YAP1 is present in the nuclei of all cells. Thereafter, YAP1 is distributed to the nuclei of outer cells or cytoplasm of inner cells, depending on the establishment of cell polarity and morula formation. However, the dynamics of YAP1 localization in other species, including ruminants, remain unclear. To gain an in-depth understanding of cell differentiation in mammalian embryos, we investigated YAP1 localization changes in bovine embryos. Unlike in mouse morulae, YAP1 displayed cytoplasmic localization in most cells, including the outer cells of bovine morulae, after the 32-cell stage. Next, we analyzed the relationship between cell polarity and nuclear localization of YAP1. Polarization of outer cells in the bovine morula began at the late 16-cell stage and was established by the late 32-cell stage, indicating that polarization preceded the nuclear localization of YAP1 in bovine embryos. To explore the regulation of YAP1 localization in bovine morula, we analyzed zona-free embryos and found that the presence of the zona pellucida significantly enhanced YAP1 cytoplasmic localization. Moreover, we observed ectopic expression of SOX2 in zona-free blastocysts, which indicated that cytoplasmic localization of YAP1 was associated with the suppression of pluripotency in the trophectoderm. These findings provide valuable insights into the molecular mechanisms underlying the first cell differentiation in mammalian embryos.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108429"},"PeriodicalIF":4.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143674027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The guanine nucleotide exchange factor Ric-8A regulates the sensitivity of constitutively active Gαq to the inhibitor YM-254890. 鸟嘌呤核苷酸交换因子 Ric-8A 可调节组成型活性 Gαq 对抑制剂 YM-254890 的敏感性。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-19 DOI: 10.1016/j.jbc.2025.108426

Morgan B Dwyer, Jiansong Luo, Tyson D Todd, Kendall J Blumer, Gregory G Tall, Philip B Wedegaertner

{"title":"The guanine nucleotide exchange factor Ric-8A regulates the sensitivity of constitutively active Gαq to the inhibitor YM-254890.","authors":"Morgan B Dwyer, Jiansong Luo, Tyson D Todd, Kendall J Blumer, Gregory G Tall, Philip B Wedegaertner","doi":"10.1016/j.jbc.2025.108426","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108426","url":null,"abstract":"Heterotrimeric G proteins are stimulated under normal circumstances by G protein coupled receptors (GPCRs) to promote downstream intracellular signaling. Mutations can occur in αq at glutamine 209 (Q209) that cause constitutive, GPCR-independent signaling due to disruption of GTPase activity. Specifically, Q209L/P mutations are oncogenic drivers of uveal melanoma. YM-254890 (YM) has been shown to selectively inhibit both wildtype and constitutively active (CA) αqQ209L/P by preventing the release of GDP and exchange for GTP, thereby halting downstream signaling. Because αqQL/P are thought to be primarily GTP-bound and GTPase deficient, the current mechanistic understanding of YM inhibition needs further investigation to clarify how a GDP-dissociation inhibitor (GDI) could potently inhibit these oncogenic mutants. Here, we expand on the current knowledge of CA αq cellular regulation by demonstrating a direct role for the αq chaperone and guanine-nucleotide exchange factor (GEF) Ric-8A in YM sensitivity. Through signaling assays in RIC-8A knockout cells, we found that myristoylated αqQL/P mutants (αqAG-QL/P), previously demonstrated to be YM-resistant, became YM-sensitive, and this was reversed by reintroduction of Ric-8A. Additionally, αqQL demonstrated increased YM sensitivity in the absence of Ric-8A, which was directly altered by the reintroduction of Ric-8A. Pulldown and BRET assays with the RGS-homology domain of GRK2, which can only bind activated αq, further demonstrated that Ric-8A expression enhances activation of αq, its ability to bind effectors, and therefore its ability to signal. With the understanding of YM acting as a GDI, we propose that Ric-8A hinders YM inhibitory effects by promoting GTP-bound, activated αqQL/P.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108426"},"PeriodicalIF":4.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143674028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interaction between Ca_V2.1 and Junctophilin3/4 depends on the II-III loop of Ca_V2.1 and on the α-helical region of Junctophilin3/4. CaV2.1与Junctophilin3/4之间的相互作用取决于CaV2.1的II-III环和Junctophilin3/4的α螺旋区。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-03-19 DOI: 10.1016/j.jbc.2025.108424

Stefano Perni, Alexander Polster, Kurt G Beam

{"title":"Interaction between CaV2.1 and Junctophilin3/4 depends on the II-III loop of CaV2.1 and on the α-helical region of Junctophilin3/4.","authors":"Stefano Perni, Alexander Polster, Kurt G Beam","doi":"10.1016/j.jbc.2025.108424","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.108424","url":null,"abstract":"Neuronal Junctophilins (JPH3 and JPH4) form junctions between the endoplasmic reticulum (ER) and plasma membrane (PM) through their C-terminal transmembrane domain, which is embedded in the ER membrane, and N-terminal domain, which binds to the PM. JPHs also recruit and slow the inactivation of the voltage-gated Ca2+ channel CaV2.1. Here, we identified the domains responsible for CaV2.1/JPH interactions by co-expressing the isolated GFP-tagged CaV2.1 cytoplasmic domains with mCherry-tagged JPH3/4 in tsA201 cells. Among the CaV2.1 domains, only the II-III loop colocalized with JPH3 and JPH4 as well as with the TM truncated JPH3-ΔTM and JPH4-ΔTM constructs, which cannot form ER-PM junctions. Further fragmentation of the II-III loop showed that both JPH-ΔTM constructs colocalized with the proximal half of the loop containing the synprint domain, known to bind presynaptic proteins, but only JPH4-ΔTM colocalized with the distal half and only JPH4 slowed the inactivation of a CaV2.1 construct lacking most of the synprint region. JPH colocalization with the II-III loop persisted when JPH divergent and transmembrane domains were deleted but was lost when the α-helical domain was also removed. Swapping the α-helical domains between JPH3 and JPH4 led to a corresponding exchange in their ability to interact with the II-III loop distal segment. Thus, the α-helical domain appears necessary for JPH binding to the synprint-containing II-III loop half and for the differential binding of JPH3 and JPH4 to the loop distal half. Furthermore, the binding of JPH α-helical domain to the CaV2.1 II-III loop is essential for slowing CaV2.1 inactivation.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"108424"},"PeriodicalIF":4.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143674026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0