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Szodorai E, Hevesi Z, Wagner L, Hökfelt TGM, Harkany T, Schnell R. A hydrophobic groove in secretagogin allows for alternate interactions with SNAP-25 and syntaxin-4 in endocrine tissues. Proc Natl Acad Sci U S A 2024; 121:e2309211121. [PMID: 38593081 PMCID: PMC11032447 DOI: 10.1073/pnas.2309211121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 03/09/2024] [Indexed: 04/11/2024] Open
Abstract
Vesicular release of neurotransmitters and hormones relies on the dynamic assembly of the exocytosis/trans-SNARE complex through sequential interactions of synaptobrevins, syntaxins, and SNAP-25. Despite SNARE-mediated release being fundamental for intercellular communication in all excitable tissues, the role of auxiliary proteins modulating the import of reserve vesicles to the active zone, and thus, scaling repetitive exocytosis remains less explored. Secretagogin is a Ca2+-sensor protein with SNAP-25 being its only known interacting partner. SNAP-25 anchors readily releasable vesicles within the active zone, thus being instrumental for 1st phase release. However, genetic deletion of secretagogin impedes 2nd phase release instead, calling for the existence of alternative protein-protein interactions. Here, we screened the secretagogin interactome in the brain and pancreas, and found syntaxin-4 grossly overrepresented. Ca2+-loaded secretagogin interacted with syntaxin-4 at nanomolar affinity and 1:1 stoichiometry. Crystal structures of the protein complexes revealed a hydrophobic groove in secretagogin for the binding of syntaxin-4. This groove was also used to bind SNAP-25. In mixtures of equimolar recombinant proteins, SNAP-25 was sequestered by secretagogin in competition with syntaxin-4. Kd differences suggested that secretagogin could shape unidirectional vesicle movement by sequential interactions, a hypothesis supported by in vitro biological data. This mechanism could facilitate the movement of transport vesicles toward release sites, particularly in the endocrine pancreas where secretagogin, SNAP-25, and syntaxin-4 coexist in both α- and β-cells. Thus, secretagogin could modulate the pace and fidelity of vesicular hormone release by differential protein interactions.
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Affiliation(s)
- Edit Szodorai
- Division of Molecular and Cellular Neuroendocrinology, Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, SolnaSE-17165, Sweden
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, ViennaA-1090, Austria
| | - Zsofia Hevesi
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, ViennaA-1090, Austria
| | - Ludwig Wagner
- Department of Internal Medicine III, Medical University of Vienna, ViennaA-1090, Austria
| | - Tomas G. M. Hökfelt
- Division of Molecular and Cellular Neuroendocrinology, Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, SolnaSE-17165, Sweden
| | - Tibor Harkany
- Division of Molecular and Cellular Neuroendocrinology, Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, SolnaSE-17165, Sweden
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, ViennaA-1090, Austria
| | - Robert Schnell
- Division of Molecular and Cellular Neuroendocrinology, Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, SolnaSE-17165, Sweden
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2
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Hong Y, Lv Z, Xing Z, Xu H, Chand H, Wang J, Li Y. Identification of molecular subtypes and diagnostic model in clear cell renal cell carcinoma based on collagen-related genes may predict the response of immunotherapy. Front Pharmacol 2024; 15:1325447. [PMID: 38375034 PMCID: PMC10875022 DOI: 10.3389/fphar.2024.1325447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 01/22/2024] [Indexed: 02/21/2024] Open
Abstract
Background: Collagen represents a prominent constituent of the tumor's extracellular matrix (ECM). Nonetheless, its correlation with the molecular subtype attributes of clear cell renal cell carcinoma (ccRCC) remains elusive. Our objective is to delineate collagen-associated molecular subtypes and further construct diagnostic model, offering insights conducive to the precise selection of ccRCC patients for immunotherapeutic interventions. Methods: We performed unsupervised non-negative matrix factorization (NMF) analysis on TCGA-KIRC samples, utilizing a set of 33 collagen-related differentially expressed genes (33CRDs) for clustering. Our analysis encompassed evaluations of subtype-associated differences in pathways, immune profiles, and somatic mutations. Through weighted gene co-expression network analysis (WGCNA) and four machine learning algorithms, two core genes were found and a diagnostic model was constructed. This was subsequently validated in a clinical immunotherapy cohort. Single cell sequencing analysis and experiments demonstrated the role of core genes in ccRCC. Finally, we also analyzed the roles of MMP9 and SCGN in pan-cancer. Results: We described two novel collagen related molecular subtypes in ccRCC, designated subtype 1 and subtype 2. Compared with subtype 1, subtype 2 showed more infiltration of immune components, but had a higher TIDE (tumor immunedysfunctionandexclusion) score and increased levels of immune checkpoint molecules. Furthermore, reduced prognosis for subtype 2 was a consistent finding in both high and low mutation load subgroups. MMP9 and SCGN were identified as key genes for distinguishing subtype 1 and subtype 2. The diagnostic model based on them could better distinguish the subtype of patients, and the differentiated patients had different progression free survival (PFS) in the clinical immunotherapy cohort. MMP9 was predominantly expressed in macrophages and has been extensively documented in the literature. Meanwhile, SCGN, which was overexpressed in tumor cells, underwent experimental validation, emphasizing its role in ccRCC. In various cancers, MMP9 and SCGN were associated with immune-related molecules and immune cells. Conclusion: Our study identifies two collagen-related molecular subtypes of ccRCC and constructs a diagnostic model to help select appropriate patients for immunotherapy.
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Affiliation(s)
- Yulong Hong
- Department of Urology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhengtong Lv
- Department of Urology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Zhuo Xing
- Department of Urology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Haozhe Xu
- Department of Urology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Harripersaud Chand
- Department of Urology, New Amsterdam Regional Hospital, New Amsterdam, Guyana
| | - Jianxi Wang
- Department of Urology, The Third Hospital of Changsha, Changsha, Hunan, China
| | - Yuan Li
- Department of Urology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
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3
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Bret H, Gao J, Zea DJ, Andreani J, Guerois R. From interaction networks to interfaces, scanning intrinsically disordered regions using AlphaFold2. Nat Commun 2024; 15:597. [PMID: 38238291 PMCID: PMC10796318 DOI: 10.1038/s41467-023-44288-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 12/07/2023] [Indexed: 01/22/2024] Open
Abstract
The revolution brought about by AlphaFold2 opens promising perspectives to unravel the complexity of protein-protein interaction networks. The analysis of interaction networks obtained from proteomics experiments does not systematically provide the delimitations of the interaction regions. This is of particular concern in the case of interactions mediated by intrinsically disordered regions, in which the interaction site is generally small. Using a dataset of protein-peptide complexes involving intrinsically disordered regions that are non-redundant with the structures used in AlphaFold2 training, we show that when using the full sequences of the proteins, AlphaFold2-Multimer only achieves 40% success rate in identifying the correct site and structure of the interface. By delineating the interaction region into fragments of decreasing size and combining different strategies for integrating evolutionary information, we manage to raise this success rate up to 90%. We obtain similar success rates using a much larger dataset of protein complexes taken from the ELM database. Beyond the correct identification of the interaction site, our study also explores specificity issues. We show the advantages and limitations of using the AlphaFold2 confidence score to discriminate between alternative binding partners, a task that can be particularly challenging in the case of small interaction motifs.
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Affiliation(s)
- Hélène Bret
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Jinmei Gao
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Diego Javier Zea
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Jessica Andreani
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
| | - Raphaël Guerois
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
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4
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Zhao L, Deng H, Yang Q, Tang Y, Zhao J, Li P, Zhang S, Yong X, Li T, Billadeau DD, Jia D. FAM91A1-TBC1D23 complex structure reveals human genetic variations susceptible for PCH. Proc Natl Acad Sci U S A 2023; 120:e2309910120. [PMID: 37903274 PMCID: PMC10636324 DOI: 10.1073/pnas.2309910120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/03/2023] [Indexed: 11/01/2023] Open
Abstract
Pontocerebellar hypoplasia (PCH) is a group of rare neurodevelopmental disorders with limited diagnostic and therapeutic options. Mutations in WDR11, a subunit of the FAM91A1 complex, have been found in patients with PCH-like symptoms; however, definitive evidence that the mutations are causal is still lacking. Here, we show that depletion of FAM91A1 results in developmental defects in zebrafish similar to that of TBC1D23, an established PCH gene. FAM91A1 and TBC1D23 directly interact with each other and cooperate to regulate endosome-to-Golgi trafficking of KIAA0319L, a protein known to regulate axonal growth. Crystal structure of the FAM91A1-TBC1D23 complex reveals that TBC1D23 binds to a conserved surface on FAM91A1 by assuming a Z-shaped conformation. More importantly, the interaction between FAM91A1 and TBC1D23 can be used to predict the risk of certain TBC1D23-associated mutations to PCH. Collectively, our study provides a molecular basis for the interaction between TBC1D23 and FAM91A1 and suggests that disrupted endosomal trafficking underlies multiple PCH subtypes.
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Affiliation(s)
- Lin Zhao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Huaqing Deng
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Qing Yang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Yingying Tang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Jia Zhao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Ping Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Sitao Zhang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Xin Yong
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Tianxing Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
| | - Daniel D. Billadeau
- Division of Oncology Research and Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN55905
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu610041, China
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5
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Tapia-González S, DeFelipe J. Secretagogin as a marker to distinguish between different neuron types in human frontal and temporal cortex. Front Neuroanat 2023; 17:1210502. [PMID: 38020216 PMCID: PMC10646422 DOI: 10.3389/fnana.2023.1210502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 09/28/2023] [Indexed: 12/01/2023] Open
Abstract
The principal aim of the present work was to chemically characterize the population of neurons labeled for the calcium binding protein secretagogin (SCGN) in the human frontal and temporal cortices (Brodmann's area 10 and 21, respectively). Both cortical regions are involved in many high cognitive functions that are especially well developed (or unique) in humans, but with different functional roles. The pattern of SCGN immunostaining was rather similar in BA10 and BA21, with all the labeled neurons displaying a non-pyramidal morphology (interneurons). Although SCGN cells were present throughout all layers, they were more frequently observed in layers II, III and IV, whereas in layer I they were found only occasionally. We examined the degree of colocalization of SCGN with parvalbumin (PV) and calretinin (CR), as well as with nitric oxide synthase (nNOS; the enzyme responsible for the synthesis of nitric oxide by neurons) by triple immunostaining. We looked for possible similarities or differences in the coexpression patterns of SCGN with PV, CR and nNOS between BA10 and BA21 throughout the different cortical layers (I-VI). The percentage of colocalization was estimated by counting the number of all labeled cells through columns (1,100-1,400 μm wide) across the entire thickness of the cortex (from the pial surface to the white matter) in 50 μm-thick sections. Several hundred neurons were examined in both cortical regions. We found that SCGN cells include multiple neurochemical subtypes, whose abundance varies according to the cortical area and layer. The present results further highlight the regional specialization of cortical neurons and underline the importance of performing additional experiments to characterize the subpopulation of SCGN cells in the human cerebral cortex in greater detail.
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Affiliation(s)
- Silvia Tapia-González
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid, Spain
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Laboratorio de Neurofisiología Celular, Facultad de Medicina, Universidad San Pablo-CEU, CEU Universities, Madrid, Spain
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid, Spain
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
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6
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Wang QW, Qin J, Chen YF, Tu Y, Xing YY, Wang Y, Yang LY, Lu SY, Geng L, Shi W, Yang Y, Yao J. 16p11.2 CNV gene Doc2α functions in neurodevelopment and social behaviors through interaction with Secretagogin. Cell Rep 2023; 42:112691. [PMID: 37354460 DOI: 10.1016/j.celrep.2023.112691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 04/22/2023] [Accepted: 06/08/2023] [Indexed: 06/26/2023] Open
Abstract
Copy-number variations (CNVs) of the human 16p11.2 genetic locus are associated with neurodevelopmental disorders, including autism spectrum disorders (ASDs) and schizophrenia. However, it remains largely unclear how this locus is involved in the disease pathogenesis. Doc2α is localized within this locus. Here, using in vivo and ex vivo electrophysiological and morphological approaches, we show that Doc2α-deficient mice have neuronal morphological abnormalities and defects in neural activity. Moreover, the Doc2α-deficient mice exhibit social and repetitive behavioral deficits. Furthermore, we demonstrate that Doc2α functions in behavioral and neural phenotypes through interaction with Secretagogin (SCGN). Finally, we demonstrate that SCGN functions in social/repetitive behaviors, glutamate release, and neuronal morphology of the mice through its Doc2α-interacting activity. Therefore, Doc2α likely contributes to neurodevelopmental disorders through its interaction with SCGN.
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Affiliation(s)
- Qiu-Wen Wang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Junhong Qin
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China; School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yan-Fen Chen
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yingfeng Tu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China; School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yun-Yun Xing
- Jiangsu Key Laboratory of Language and Cognitive Neuroscience, School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou 221116, China; Jiangsu Collaborative Innovation Center for Language Ability, Xuzhou 221009, China
| | - Yuchen Wang
- School of Engineering Medicine and School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Lv-Yu Yang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Si-Yao Lu
- Jiangsu Key Laboratory of Language and Cognitive Neuroscience, School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou 221116, China; Jiangsu Collaborative Innovation Center for Language Ability, Xuzhou 221009, China
| | - Libo Geng
- Jiangsu Key Laboratory of Language and Cognitive Neuroscience, School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou 221116, China; Jiangsu Collaborative Innovation Center for Language Ability, Xuzhou 221009, China
| | - Wei Shi
- School of Engineering Medicine and School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
| | - Yiming Yang
- Jiangsu Key Laboratory of Language and Cognitive Neuroscience, School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou 221116, China; Jiangsu Collaborative Innovation Center for Language Ability, Xuzhou 221009, China.
| | - Jun Yao
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Beijing 100084, China.
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7
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Guo C, Zhang T, Tang J, Gao C, Zhou Z, Li C. Construction of PLGA Porous Microsphere-Based Artificial Pancreatic Islets Assisted by the Cell Centrifugation Perfusion Technique. ACS OMEGA 2023; 8:15288-15297. [PMID: 37151553 PMCID: PMC10157690 DOI: 10.1021/acsomega.3c00424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 04/06/2023] [Indexed: 05/09/2023]
Abstract
Pancreatic islet transplantation is a promising treatment that could potentially reverse diabetes, but its clinical applicability is severely limited by a shortage of organ donors. Various cell loading approaches using polymeric porous microspheres (PMs) have been developed for tissue regeneration; however, PM-based multicellular artificial pancreatic islets' construction has been scarcely reported. In this study, MIN6 (a mouse insulinoma cell line) and MS1 (a mouse pancreatic islet endothelial cell line) cells were seeded into poly(lactic-co-glycolic acid) (PLGA) PMs via an upgraded centrifugation-based cell perfusion seeding technique invented and patented by our group. Cell morphology, distribution, viability, migration, and proliferation were all evaluated. Results from glucose-stimulated insulin secretion (GSIS) assay and RNA-seq analysis suggested that MIN6 and MS1-loaded PLGA PMs exhibited better glucose responsiveness, which is partly attributable to vascular formation during PM-dependent islet construction. The present study suggests that the PLGA PM-based artificial pancreatic islets may provide an alternative strategy for the potential treatment of diabetes in the future.
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Affiliation(s)
- Chuanjia Guo
- Biomedical
Barriers Research Center, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union
Medical College, Tianjin Key Laboratory of Biomedical Materials, Tianjin 300192, China
| | - Tong Zhang
- Clinical
Laboratory, Tianjin Hospital, Tianjin 300211, China
| | - Jianghai Tang
- Biomedical
Barriers Research Center, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union
Medical College, Tianjin Key Laboratory of Biomedical Materials, Tianjin 300192, China
| | - Chang Gao
- Biomedical
Barriers Research Center, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union
Medical College, Tianjin Key Laboratory of Biomedical Materials, Tianjin 300192, China
| | - Zhimin Zhou
- Biomedical
Barriers Research Center, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union
Medical College, Tianjin Key Laboratory of Biomedical Materials, Tianjin 300192, China
- ,
| | - Chen Li
- Biomedical
Barriers Research Center, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union
Medical College, Tianjin Key Laboratory of Biomedical Materials, Tianjin 300192, China
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8
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SCGN deficiency is a risk factor for autism spectrum disorder. Signal Transduct Target Ther 2023; 8:3. [PMID: 36588101 PMCID: PMC9806109 DOI: 10.1038/s41392-022-01225-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/15/2022] [Accepted: 09/30/2022] [Indexed: 01/03/2023] Open
Abstract
Autism spectrum disorder (ASD) affects 1-2% of all children and poses a great social and economic challenge for the globe. As a highly heterogeneous neurodevelopmental disorder, the development of its treatment is extremely challenging. Multiple pathways have been linked to the pathogenesis of ASD, including signaling involved in synaptic function, oxytocinergic activities, immune homeostasis, chromatin modifications, and mitochondrial functions. Here, we identify secretagogin (SCGN), a regulator of synaptic transmission, as a new risk gene for ASD. Two heterozygous loss-of-function mutations in SCGN are presented in ASD probands. Deletion of Scgn in zebrafish or mice leads to autism-like behaviors and impairs brain development. Mechanistically, Scgn deficiency disrupts the oxytocin signaling and abnormally activates inflammation in both animal models. Both ASD probands carrying Scgn mutations also show reduced oxytocin levels. Importantly, we demonstrate that the administration of oxytocin and anti-inflammatory drugs can attenuate ASD-associated defects caused by SCGN deficiency. Altogether, we identify a convergence between a potential autism genetic risk factor SCGN, and the pathological deregulation in oxytocinergic signaling and immune responses, providing potential treatment for ASD patients suffering from SCGN deficiency. Our study also indicates that it is critical to identify and stratify ASD patient populations based on their disease mechanisms, which could greatly enhance therapeutic success.
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9
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ox-LDL induces autophagy-mediated apoptosis by suppressing secretagogin-regulated autophagic flux in pancreatic β-cells. Acta Biochim Biophys Sin (Shanghai) 2022; 54:1822-1831. [PMID: 36789686 PMCID: PMC10157621 DOI: 10.3724/abbs.2022186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Lipotoxicity has been shown to induce the loss of functional β-cell mass and lead to type 2 diabetes, but the mechanism remains unknown. In this study, we aim to explore the role of secretagogin (SCGN) in lipotoxicity-induced β-cell injury. Our results indicate that ox-LDL treatment leads to autophagic cell death, as evidenced by decreased cell viability, aggravated cell apoptosis, and the accumulation of the p62 protein in MIN6 cells. LysoTracker Red staining, TEM and mRFP-GFP-LC3 assays demonstrate that autophagic flux is blocked in ox-LDL-treated MIN6 cells. Intriguingly, SCGN is significantly decreased in MIN6 cells under lipotoxic conditions. Additionally, siRNA-guided SCGN knockdown blocks autophagic flux triggered by rapamycin, while SCGN restoration alleviates autophagic flux retardation and mitigates cell apoptosis. The physical interaction between SCGN and SNAP29 is validated by bioinformatics analysis, coimmunoprecipitation assay and SCGN knockdown test. Downregulation of SCGN expression reduces the interaction of these two proteins. Taken together, our results indicate that ox-LDL treatment induces apoptotic β-cell death by blocking autophagic flux dependent on SCGN downregulation. SCGN administration prevents lipotoxic β-cell injury and may be a potential therapeutic strategy to promote β-cell expansion in type 2 diabetes.
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Biancolin AD, Srikrishnaraj A, Jeong H, Martchenko A, Brubaker PL. The Cytoskeletal Transport Protein, Secretagogin, Is Essential for Diurnal Glucagon-like Peptide-1 Secretion in Mice. Endocrinology 2022; 163:6678475. [PMID: 36036556 DOI: 10.1210/endocr/bqac142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Indexed: 11/19/2022]
Abstract
The intestinal L-cell incretin, glucagon-like peptide-1 (GLP-1), exhibits a circadian pattern of secretion, thereby entraining diurnal insulin release. Secretagogin (Scgn), an actin-binding regulatory protein, is essential for the temporal peak of GLP-1 secretion in vitro. To interrogate the role of Scgn in diurnal GLP-1 secretion in vivo, peak and trough GLP-1 release were evaluated in knockout mice (Scgn-/-, Gcg-CreERT2/+; Scgnfl/fl and Vil-CreERT2/+; Scgnfl/fl), and RNA sequencing (RNA-Seq) was conducted in Scgn knockdown L-cells. All 3 knockout models demonstrated loss of the diurnal rhythm of GLP-1 secretion in response to oral glucose. Gcg-CreERT2/+; Scgnfl/fl mice also lost the normal pattern in glucagon secretion, while Scgn-/- and Vil-CreERT2/+; Scgnfl/fl animals demonstrated impaired diurnal secretion of the related incretin, glucose-dependent insulinotrophic polypeptide. RNA-Seq of mGLUTag L-cells showed decreased pathways regulating vesicle transport, transport and binding, and protein-protein interaction at synapse, as well as pathways related to proteasome-mediated degradation including chaperone-mediated protein complex assembly following Scgn knockdown. Scgn is therefore essential for diurnal L-cell GLP-1 secretion in vivo, likely mediated through effects on secretory granule dynamics.
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Affiliation(s)
| | - Arjuna Srikrishnaraj
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Hyerin Jeong
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Alexandre Martchenko
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Patricia Lee Brubaker
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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11
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Chidananda AH, Khandelwal R, Jhamkhindikar A, Pawar AD, Sharma AK, Sharma Y. Secretagogin is a Ca 2+-dependent stress-responsive chaperone that may also play a role in aggregation-based proteinopathies. J Biol Chem 2022; 298:102285. [PMID: 35870554 PMCID: PMC9425029 DOI: 10.1016/j.jbc.2022.102285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 07/01/2022] [Accepted: 07/05/2022] [Indexed: 11/17/2022] Open
Abstract
Secretagogin (SCGN) is a three-domain hexa-EF-hand Ca2+-binding protein that plays a regulatory role in the release of several hormones. SCGN is expressed largely in pancreatic β-cells, certain parts of the brain, and also in neuroendocrine tissues. The expression of SCGN is altered in several diseases, such as diabetes, cancers, and neurodegenerative disorders; however, the precise associations that closely link SCGN expression to such pathophysiologies are not known. In this work, we report that SCGN is an early responder to cellular stress, and SCGN expression is temporally upregulated by oxidative stress and heat shock. We show the overexpression of SCGN efficiently prevents cells from heat shock and oxidative damage. We further demonstrate that in the presence of Ca2+, SCGN efficiently prevents the aggregation of a broad range of model proteins in vitro. Small-angle X-ray scattering (BioSAXS) studies further reveal that Ca2+ induces the conversion of a closed compact apo-SCGN conformation into an open extended holo-SCGN conformation via multistate intermediates, consistent with the augmentation of chaperone activity of SCGN. Furthermore, isothermal titration calorimetry establishes that Ca2+ enables SCGN to bind α-synuclein and insulin, two target proteins of SCGN. Altogether, our data not only demonstrate that SCGN is a Ca2+-dependent generic molecular chaperone involved in protein homeostasis with broad substrate specificity but also elucidate the origin of its altered expression in several cancers. We describe a plausible mechanism of how perturbations in Ca2+ homeostasis and/or deregulated SCGN expression would hasten the process of protein misfolding, which is a feature of many aggregation-based proteinopathies.
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Affiliation(s)
- Amrutha H Chidananda
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad-500 007, India
| | - Radhika Khandelwal
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad-500 007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Aditya Jhamkhindikar
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad-500 007, India
| | - Asmita D Pawar
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad-500 007, India; Indian Institute of Scientific and Education Research (IISER), Berhampur-760010, India
| | - Anand K Sharma
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad-500 007, India.
| | - Yogendra Sharma
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad-500 007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India; Indian Institute of Scientific and Education Research (IISER), Berhampur-760010, India.
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12
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Khan S. Endoplasmic Reticulum in Metaplasticity: From Information Processing to Synaptic Proteostasis. Mol Neurobiol 2022; 59:5630-5655. [PMID: 35739409 DOI: 10.1007/s12035-022-02916-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 06/05/2022] [Indexed: 11/29/2022]
Abstract
The ER (endoplasmic reticulum) is a Ca2+ reservoir and the unique protein-synthesizing machinery which is distributed throughout the neuron and composed of multiple different structural domains. One such domain is called EMC (endoplasmic reticulum membrane protein complex), pleiotropic nature in cellular functions. The ER/EMC position inside the neurons unmasks its contribution to synaptic plasticity via regulating various cellular processes from protein synthesis to Ca2+ signaling. Since presynaptic Ca2+ channels and postsynaptic ionotropic receptors are organized into the nanodomains, thus ER can be a crucial player in establishing TMNCs (transsynaptic molecular nanocolumns) to shape efficient neural communications. This review hypothesized that ER is not only involved in stress-mediated neurodegeneration but also axon regrowth, remyelination, neurotransmitter switching, information processing, and regulation of pre- and post-synaptic functions. Thus ER might not only be a protein-synthesizing and quality control machinery but also orchestrates plasticity of plasticity (metaplasticity) within the neuron to execute higher-order brain functions and neural repair.
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Affiliation(s)
- Shumsuzzaman Khan
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA.
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13
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Basu S, Mitra S, Singh O, Chandramohan B, Singru PS. Secretagogin in the brain and pituitary of the catfish, Clarias batrachus: Molecular characterization and regulation by insulin. J Comp Neurol 2022; 530:1743-1772. [PMID: 35322425 DOI: 10.1002/cne.25311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 02/02/2022] [Accepted: 02/04/2022] [Indexed: 11/12/2022]
Abstract
Secretagogin (scgn), is a novel hexa EF-hand, phylogenetically conserved calcium-binding protein. It serves as Ca2+ sensor and participates in Ca2+ -signaling and neuroendocrine regulation in mammals. However, its relevance in the brain of non-mammalian vertebrates has largely remained unexplored. To address this issue, we studied the cDNA encoding scgn, scgn mRNA expression, and distribution of scgn-equipped elements in the brain and pituitary of a teleost, Clarias batrachus (cb). The cbscgn cDNA consists of three transcripts (T) variants: T1 (2185 bp), T2 (2151 bp) and T3 (2060 bp). While 816 bp ORF in T1 and T2 encodes highly conserved six EF-hand 272 aa protein fully capable of Ca2+ -binding, 726-bp ORF in T3 encodes 242 aa protein. The T1 showed >90% and >70% identity with scgn of catfishes, and other teleosts and mammals, respectively. The T1-mRNA was widely expressed in the brain and pituitary, while the expression of T3 was restricted to the telencephalon. Application of the anti-scgn antiserum revealed a ∼32 kDa scgn-immunoreactive (scgn-i) band (known molecular weight of scgn) in the forebrain tissue, and immunohistochemically labeled neurons in the olfactory epithelium and bulb, telencephalon, preoptic area, hypothalamus, thalamus, and hindbrain. In the pituitary, scgn-i cells were seen in the pars distalis and intermedia. Insulin is reported to regulate scgn mRNA in the mammalian hippocampus, and feeding-related neuropeptides in the telencephalon of teleost. Intracranial injection of insulin significantly increased T1-mRNA expression and scgn-immunoreactivity in the telencephalon. We suggest that scgn may be an important player in the regulation of olfactory, neuroendocrine system, and energy balance functions in C. batrachus.
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Affiliation(s)
- Sumela Basu
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India.,Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Saptarsi Mitra
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India.,Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Omprakash Singh
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India.,Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Bathrachalam Chandramohan
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India
| | - Praful S Singru
- School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, India.,Homi Bhabha National Institute (HBNI), Mumbai, India
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14
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SNX27-FERM-SNX1 complex structure rationalizes divergent trafficking pathways by SNX17 and SNX27. Proc Natl Acad Sci U S A 2021; 118:2105510118. [PMID: 34462354 DOI: 10.1073/pnas.2105510118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The molecular events that determine the recycling versus degradation fates of internalized membrane proteins remain poorly understood. Two of the three members of the SNX-FERM family, SNX17 and SNX31, utilize their FERM domain to mediate endocytic trafficking of cargo proteins harboring the NPxY/NxxY motif. In contrast, SNX27 does not recycle NPxY/NxxY-containing cargo but instead recycles cargo containing PDZ-binding motifs via its PDZ domain. The underlying mechanism governing this divergence in FERM domain binding is poorly understood. Here, we report that the FERM domain of SNX27 is functionally distinct from SNX17 and interacts with a novel DLF motif localized within the N terminus of SNX1/2 instead of the NPxY/NxxY motif in cargo proteins. The SNX27-FERM-SNX1 complex structure reveals that the DLF motif of SNX1 binds to a hydrophobic cave surrounded by positively charged residues on the surface of SNX27. The interaction between SNX27 and SNX1/2 is critical for efficient SNX27 recruitment to endosomes and endocytic recycling of multiple cargoes. Finally, we show that the interaction between SNX27 and SNX1/2 is critical for brain development in zebrafish. Altogether, our study solves a long-standing puzzle in the field and suggests that SNX27 and SNX17 mediate endocytic recycling through fundamentally distinct mechanisms.
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15
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Model-based analysis uncovers mutations altering autophagy selectivity in human cancer. Nat Commun 2021; 12:3258. [PMID: 34059679 PMCID: PMC8166871 DOI: 10.1038/s41467-021-23539-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 04/28/2021] [Indexed: 02/07/2023] Open
Abstract
Autophagy can selectively target protein aggregates, pathogens, and dysfunctional organelles for the lysosomal degradation. Aberrant regulation of autophagy promotes tumorigenesis, while it is far less clear whether and how tumor-specific alterations result in autophagic aberrance. To form a link between aberrant autophagy selectivity and human cancer, we establish a computational pipeline and prioritize 222 potential LIR (LC3-interacting region) motif-associated mutations (LAMs) in 148 proteins. We validate LAMs in multiple proteins including ATG4B, STBD1, EHMT2 and BRAF that impair their interactions with LC3 and autophagy activities. Using a combination of transcriptomic, metabolomic and additional experimental assays, we show that STBD1, a poorly-characterized protein, inhibits tumor growth via modulating glycogen autophagy, while a patient-derived W203C mutation on LIR abolishes its cancer inhibitory function. This work suggests that altered autophagy selectivity is a frequently-used mechanism by cancer cells to survive during various stresses, and provides a framework to discover additional autophagy-related pathways that influence carcinogenesis. Although autophagy has been linked to tumourigenesis, it is unclear how genomic alterations affect autophagy selectivity in tumours. Here, the authors establish a pipeline that integrates computational and experimental approaches to show that altered autophagy selectivity is frequent in cancer cells and link glycogen autophagy with tumourigenesis.
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16
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Liu Z, Wang Y, Yang F, Yang Q, Mo X, Burstein E, Jia D, Cai XT, Tu Y. GMPPB-congenital disorders of glycosylation associate with decreased enzymatic activity of GMPPB. MOLECULAR BIOMEDICINE 2021; 2:13. [PMID: 35006422 PMCID: PMC8607393 DOI: 10.1186/s43556-021-00027-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/12/2021] [Indexed: 02/08/2023] Open
Abstract
The congenital disorders of glycosylation (CDG) are a family of metabolic diseases in which glycosylation of proteins or lipids is deficient. GDP-mannose pyrophosphorylase B (GMPPB) mutations lead to CDG, characterized by neurological and muscular defects. However, the genotype-phenotype correlation remains elusive, limiting our understanding of the underlying mechanism and development of therapeutic strategy. Here, we report a case of an individual presenting congenital muscular dystrophy with cerebellar involvement, who presents two heterozygous GMPPB mutations (V111G and G214S). The V111G mutation significantly decreases GMPPB’s enzymatic activity. By measuring enzymatic activities of 17 reported GMPPB mutants identified in patients diagnosed with GMPPB-CDG, we discover that all tested GMPPB variants exhibit significantly decreased enzymatic activity. Using a zebrafish model, we find that Gmppb is required for neuronal and muscle development, and further demonstrate that enzymatic activity of GMPPB mutants correlates with muscular and neuronal phenotypes in zebrafish. Taken together, our findings discover the importance of GMPPB enzymatic activity for the pathogenesis of GMPPB-CDG, and shed light for the development of additional indicators and therapeutic strategy.
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Affiliation(s)
- Zhe Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Yan Wang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Fan Yang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Qin Yang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Xianming Mo
- Department of Pediatric Surgery and Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Ezra Burstein
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.
| | - Xiao-Tang Cai
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.
| | - Yingfeng Tu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, State Key Laboratory of Biotherapy, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.
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17
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Cryo-EM structures of human GMPPA-GMPPB complex reveal how cells maintain GDP-mannose homeostasis. Nat Struct Mol Biol 2021; 28:1-12. [PMID: 33986552 DOI: 10.1038/s41594-021-00591-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 04/08/2021] [Indexed: 02/05/2023]
Abstract
GDP-mannose (GDP-Man) is a key metabolite essential for protein glycosylation and glycophosphatidylinositol anchor synthesis, and aberrant cellular GDP-Man levels have been associated with multiple human diseases. How cells maintain homeostasis of GDP-Man is unknown. Here, we report the cryo-EM structures of human GMPPA-GMPPB complex, the protein machinery responsible for GDP-Man synthesis, in complex with GDP-Man or GTP. Unexpectedly, we find that the catalytically inactive subunit GMPPA displays a much higher affinity to GDP-Man than the active subunit GMPPB and, subsequently, inhibits the catalytic activity of GMPPB through a unique C-terminal loop of GMPPA. Importantly, disruption of the interactions between GMPPA and GMPPB or the binding of GDP-Man to GMPPA in zebrafish leads to abnormal brain development and muscle abnormality, analogous to phenotypes observed in individuals carrying GMPPA or GMPPB mutations. We conclude that GMPPA acts as a cellular sensor to maintain mannose homeostasis through allosterically regulating GMPPB.
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18
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Vassalli QA, Colantuono C, Nittoli V, Ferraioli A, Fasano G, Berruto F, Chiusano ML, Kelsh RN, Sordino P, Locascio A. Onecut Regulates Core Components of the Molecular Machinery for Neurotransmission in Photoreceptor Differentiation. Front Cell Dev Biol 2021; 9:602450. [PMID: 33816460 PMCID: PMC8012850 DOI: 10.3389/fcell.2021.602450] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/11/2021] [Indexed: 11/13/2022] Open
Abstract
Photoreceptor cells (PRC) are neurons highly specialized for sensing light stimuli and have considerably diversified during evolution. The genetic mechanisms that underlie photoreceptor differentiation and accompanied the progressive increase in complexity and diversification of this sensory cell type are a matter of great interest in the field. A role of the homeodomain transcription factor Onecut (Oc) in photoreceptor cell formation is proposed throughout multicellular organisms. However, knowledge of the identity of the Oc downstream-acting factors that mediate specific tasks in the differentiation of the PRC remains limited. Here, we used transgenic perturbation of the Ciona robusta Oc protein to show its requirement for ciliary PRC differentiation. Then, transcriptome profiling between the trans-activation and trans-repression Oc phenotypes identified differentially expressed genes that are enriched in exocytosis, calcium homeostasis, and neurotransmission. Finally, comparison of RNA-Seq datasets in Ciona and mouse identifies a set of Oc downstream genes conserved between tunicates and vertebrates. The transcription factor Oc emerges as a key regulator of neurotransmission in retinal cell types.
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Affiliation(s)
- Quirino Attilio Vassalli
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Chiara Colantuono
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Valeria Nittoli
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Anna Ferraioli
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Giulia Fasano
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Federica Berruto
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Maria Luisa Chiusano
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Naples, Italy
- Department of Agriculture, Università degli Studi di Napoli Federico II, Portici, Italy
| | - Robert Neil Kelsh
- Department of Biology and Biochemistry and Centre for Regenerative Medicine, University of Bath, London, United Kingdom
| | - Paolo Sordino
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Annamaria Locascio
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
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19
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Mao L, Liao C, Qin J, Gong Y, Zhou Y, Li S, Liu Z, Deng H, Deng W, Sun Q, Mo X, Xue Y, Billadeau DD, Dai L, Li G, Jia D. Phosphorylation of SNX27 by MAPK11/14 links cellular stress-signaling pathways with endocytic recycling. J Cell Biol 2021; 220:211812. [PMID: 33605979 PMCID: PMC7901142 DOI: 10.1083/jcb.202010048] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/28/2020] [Accepted: 01/21/2021] [Indexed: 02/08/2023] Open
Abstract
Endocytosed proteins can be delivered to lysosomes for degradation or recycled to either the trans-Golgi network or the plasma membrane. It remains poorly understood how the recycling versus degradation of cargoes is determined. Here, we show that multiple extracellular stimuli, including starvation, LPS, IL-6, and EGF treatment, can strongly inhibit endocytic recycling of multiple cargoes through the activation of MAPK11/14. The stress-induced kinases in turn directly phosphorylate SNX27, a key regulator of endocytic recycling, at serine 51 (Ser51). Phosphorylation of SNX27 at Ser51 alters the conformation of its cargo-binding pocket and decreases the interaction between SNX27 and cargo proteins, thereby inhibiting endocytic recycling. Our study indicates that endocytic recycling is highly dynamic and can crosstalk with cellular stress–signaling pathways. Suppression of endocytic recycling and enhancement of receptor lysosomal degradation serve as new mechanisms for cells to cope with stress and save energy.
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Affiliation(s)
- Lejiao Mao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
| | - Chenyi Liao
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Jiao Qin
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
| | - Yanqiu Gong
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yifei Zhou
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
| | - Shasha Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
| | - Zhe Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
| | - Huaqing Deng
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
| | - Wankun Deng
- Department of Bioinformatics and Systems Biology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Qingxiang Sun
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xianming Mo
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yu Xue
- Department of Bioinformatics and Systems Biology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Daniel D Billadeau
- Division of Oncology Research and Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN
| | - Lunzhi Dai
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Guohui Li
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
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20
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Wu L, Lv Y, Lv Y, Xiang S, Zhao Z, Tang Z, Ou L, Yan B, Xiao X, Wen G, Cao R, Yang J. A novel secretagogin/ATF4 pathway is involved in oxidized LDL-induced endoplasmic reticulum stress and islet β-cell apoptosis. Acta Biochim Biophys Sin (Shanghai) 2021; 53:54-62. [PMID: 33289795 DOI: 10.1093/abbs/gmaa142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Indexed: 12/16/2022] Open
Abstract
Excessive accumulation of cholesterol in β cells initiates endoplasmic reticulum (ER) stress and associated apoptosis. We have reported that excessive uptake of cholesterol by MIN6 cells decreases the expression of secretagogin (SCGN) and then attenuates insulin secretion. Here, we aimed to determine whether cholesterol-induced SCGN decrease is involved in the modulation of ER stress and apoptosis in pancreatic β cells. In this study, MIN6 cells were treated with oxidized low-density lipoprotein (ox-LDL) for 24 h, and then intracellular lipid droplets and cell apoptosis were quantified, and SCGN and ER stress markers were identified by western blot analysis. Furthermore, small interfer RNA (siRNA)-mediated SCGN knockdown and recombinant plasmid-mediated SCGN restoration experiments were performed to confirm the role of SCGN in ER stress and associated cell apoptosis. Finally, the interaction of SCGN with ATF4 was computationally predicted and then validated by a co-immunoprecipitation assay. We found that ox-LDL treatment increased the levels of ER stress markers, such as phosphorylated protein kinase-like endoplasmic reticulum kinase, phosphorylated eukaryotic initiation factor 2 alpha, activating transcription factor 4 (ATF4), and transcription factor CCAAT-enhancer-binding protein homologous protein, and promoted MIN6 cell apoptosis; in addition, the expression of SCGN was downregulated. siRNA-mediated SCGN knockdown exacerbated β-cell ER stress by increasing ATF4 expression. Pretreatment of MIN6 cells with the recombinant SCGN partly antagonized ox-LDL-induced ER stress and apoptosis. Furthermore, a co-immunoprecipitation assay revealed an interaction between SCGN and ATF4 in MIN6 cells. Taken together, these results demonstrated that pancreatic β-cell apoptosis induced by ox-LDL treatment can be attributed, in part, to an SCGN/ATF4-dependent ER stress response.
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Affiliation(s)
- Li Wu
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Yuncheng Lv
- Guangxi Key Laboratory of Diabetic Systems Medicine, Guilin Medical University, Guilin 541199, China
| | - Ying Lv
- Department of Metabolism & Endocrinology, The Second Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Sunmin Xiang
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Zhibo Zhao
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Ziqing Tang
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Linling Ou
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Bin Yan
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Xinhua Xiao
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Gebo Wen
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Renxian Cao
- Department of Clinical Research, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
| | - Jing Yang
- Department of Metabolism & Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang 421001, China
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21
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Lv Y, Xiang S, Cao R, Wu L, Yang J. SCGN-regulated Stage-wise SNARE Assembly: Novel Insight into Synaptic Exocytosis. Neurosci Bull 2020; 36:1576-1578. [PMID: 33025412 DOI: 10.1007/s12264-020-00590-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 07/19/2020] [Indexed: 10/23/2022] Open
Affiliation(s)
- Ying Lv
- Department of Metabolism and Endocrinology, The Second Affiliated Hospital of the University of South China, Hengyang, 421001, China
| | - Sunmin Xiang
- Department of Metabolism and Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang, 421001, China
| | - Renxian Cao
- Department of Metabolism and Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang, 421001, China
| | - Li Wu
- Department of Metabolism and Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang, 421001, China
| | - Jing Yang
- Department of Metabolism and Endocrinology, The First Affiliated Hospital of the University of South China, Hengyang, 421001, China.
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Secretagogin is Related to Insulin Secretion but Unrelated to Gestational Diabetes Mellitus Status in Pregnancy. J Clin Med 2020; 9:jcm9072277. [PMID: 32708966 PMCID: PMC7408624 DOI: 10.3390/jcm9072277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/13/2020] [Accepted: 07/15/2020] [Indexed: 12/13/2022] Open
Abstract
Secretagogin (SCGN) is a calcium binding protein related to insulin release in the pancreas. Although SCGN is not co-released with insulin, plasma concentrations have been found to be increased in type 2 diabetes mellitus patients. Until now, no study on SCGN levels in pregnancy or patients with gestational diabetes mellitus (GDM) has been published. In 93 women of a high-risk population for GDM at the Medical University of Vienna, secretagogin levels of 45 GDM patients were compared to 48 women with a normal glucose tolerance (NGT). Glucose tolerance, insulin resistance and secretion were assessed with oral glucose tolerance tests (OGTT) between the 10th and 28th week of gestation (GW) and postpartum. In all women, however, predominantly in women with NGT, there was a significant positive correlation between SCGN levels and Stumvoll first (rp = 0.220, p = 0.032) and second phase index (rp = 0.224, p = 0.028). SCGN levels were not significantly different in women with NGT and GDM. However, SCGN was higher postpartum than during pregnancy (postpartum: 88.07 ± 35.63 pg/mL; pregnancy: 75.24 ± 37.90 pg/mL, p = 0.004). SCGN was directly correlated with week of gestation (rp = 0.308; p = 0.021) and triglycerides (rp = 0.276; p = 0.038) in women with GDM. Therefore, SCGN is related to insulin secretion and hyperinsulinemia during pregnancy; however, it does not display differences between women with NGT and GDM.
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