5tib
Gasdermin-B C-terminal domain containing the polymorphism residues Arg299:Ser306 fused to maltose binding protein
Structural highlights
FunctionGSDMB_HUMAN Precursor of a pore-forming protein that acts as a downstream mediator of granzyme-mediated cell death (PubMed:32299851). This form constitutes the precursor of the pore-forming protein: upon cleavage, the released N-terminal moiety (Gasdermin-B, N-terminal) binds to membranes and forms pores, triggering pyroptosis (PubMed:32299851). Also acts as a regulator of epithelial cell repair independently of programmed cell death: translocates to the plasma membrane and promotes epithelial maintenance and repair by regulating PTK2/FAK-mediated phosphorylation of PDGFA (PubMed:35021065).[1] [2] Pore-forming protein produced by cleavage by granzyme A (GZMA), which causes membrane permeabilization and pyroptosis in target cells of cytotoxic T and natural killer (NK) cells (PubMed:27281216, PubMed:32299851). Key downstream mediator of granzyme-mediated cell death: (1) granzyme A (GZMA), delivered to target cells from cytotoxic T- and NK-cells, (2) specifically cleaves Gasdermin-B to generate this form (PubMed:32299851). After cleavage, moves to the plasma membrane, homooligomerizes within the membrane and forms pores of 10-15 nanometers (nm) of inner diameter, triggering pyroptosis (PubMed:32299851). The different isoforms recognize and bind different phospholipids on membranes, promoting cell death of different target cells (PubMed:34022140, PubMed:36157507).[3] [4] [5] [6] Precursor of a pore-forming protein that acts as a downstream mediator of granzyme-mediated cell death and mediates pyroptosis of host human cells (PubMed:28154144, PubMed:36157507). Following cleavage and activation by granzyme A (GZMA), the N-terminal part binds to membrane inner leaflet lipids, homooligomerizes within the human plasma membrane and forms pores of 10-15 nanometers (nm) of inner diameter, triggering pyroptosis (PubMed:28154144, PubMed:36157507). Recognizes and binds membrane inner leaflet lipids of human cells, such as phosphatidylinositol 4-phosphate, phosphatidylinositol 5-phosphate, bisphosphorylated phosphatidylinositols, such as phosphatidylinositol (4,5)-bisphosphate, and more weakly to phosphatidic acid (PubMed:28154144, PubMed:36157507). Also binds sufatide, a component of the apical membrane of epithelial cells (PubMed:28154144).[7] [8] Precursor of a pore-forming protein that acts as a downstream mediator of granzyme-mediated cell death and specifically mediates cell death of Gram-negative bacteria in response to infection (PubMed:34022140). Following cleavage and activation by granzyme A (GZMA), the N-terminal part recognizes and binds phospholipids found on Gram-negative bacterial membranes, such as lipid A and cariolipin, homooligomerizes within the bacterial membranes and forms pores, triggering cell death (PubMed:34022140). In contrast to isoform 4, does not bind to membrane inner leaflet lipids of host human cell, such as phosphatidylinositol 4-phosphate, phosphatidylinositol 5-phosphate, bisphosphorylated phosphatidylinositols, such as phosphatidylinositol (4,5)-bisphosphate (PubMed:34022140).[9] Publication Abstract from PubMedThe exact function of human gasdermin-B (GSDMB), which regulates differentiation and growth of epithelial cells, is yet to be elucidated. In human epidermal growth factor receptor 2 (HER2)-positive breast cancer, GSDMB gene amplification and protein overexpression indicate a poor response to HER2-targeted therapy. Genome-wide association studies revealed a correlation between GSDMB SNPs and an increased susceptibility to Crohn's disease, ulcerative colitis, and asthma. The N- and C-terminal domains of all gasdermins possess lipid-binding and regulatory activities, respectively. Inflammatory caspases cleave gasdermin-D in the interdomain linker but not GSDMB. The cleaved N-terminal domain binds phosphoinositides and cardiolipin, forms membrane-disrupting pores, and executes pyroptosis. We show that both full-length GSDMB and the N-terminal domain bind to nitrocellulose membranes immobilized with phosphoinositides or sulfatide, but not with cardiolipin. In addition, the GSDMB N-terminal domain binds liposomes containing sulfatide. The crystal structure of the GSDMB C-terminal domain reveals the structural impact of the amino acids encoded by SNPs that are linked to asthma and inflammatory bowel disease (IBD). A loop that carries the polymorphism amino acids corresponding to healthy individuals (Gly299:Pro306) exhibits high conformational flexibility, whereas the loop carrying amino acids found in individuals with increased disease risk (Arg299:Ser306) exhibits a well-defined conformation and higher positive surface charge. Apoptotic executioner caspase-3, -6, and -7, but not the inflammatory caspases, cleave GSDMB at 88DNVD91 within the N-terminal domain. Selective sulfatide binding may indicate possible function for GSDMB in the cellular sulfatide transport. Gene polymorphism linked to increased asthma and IBD risk alters gasdermin-B structure, a sulfatide and phosphoinositide binding protein.,Chao KL, Kulakova L, Herzberg O Proc Natl Acad Sci U S A. 2017 Feb 14;114(7):E1128-E1137. doi:, 10.1073/pnas.1616783114. Epub 2017 Feb 1. PMID:28154144[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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