caspase-9 / response to G1 DNA damage checkpoint signaling / caspase complex / cytochrome c-heme linkage / Formation of apoptosome / regulation of apoptotic DNA fragmentation / apoptosome / cytochrome complex / activation of cysteine-type endopeptidase activity involved in apoptotic process by cytochrome c / leukocyte apoptotic process ...caspase-9 / response to G1 DNA damage checkpoint signaling / caspase complex / cytochrome c-heme linkage / Formation of apoptosome / regulation of apoptotic DNA fragmentation / apoptosome / cytochrome complex / activation of cysteine-type endopeptidase activity involved in apoptotic process by cytochrome c / leukocyte apoptotic process / glial cell apoptotic process / response to cobalt ion / cysteine-type endopeptidase activity involved in apoptotic signaling pathway / positive regulation of cysteine-type endopeptidase activity / Caspase activation via Dependence Receptors in the absence of ligand / Activation of caspases through apoptosome-mediated cleavage / Regulation of the apoptosome activity / cysteine-type endopeptidase activity involved in apoptotic process / SMAC (DIABLO) binds to IAPs / SMAC(DIABLO)-mediated dissociation of IAP:caspase complexes / AKT phosphorylates targets in the cytosol / mitochondrial electron transport, cytochrome c to oxygen / fibroblast apoptotic process / epithelial cell apoptotic process / platelet formation / mitochondrial electron transport, ubiquinol to cytochrome c / TP53 Regulates Transcription of Caspase Activators and Caspases / Transcriptional Regulation by E2F6 / Constitutive Signaling by AKT1 E17K in Cancer / cysteine-type endopeptidase activator activity involved in apoptotic process / positive regulation of cysteine-type endopeptidase activity involved in apoptotic process / protein maturation / : / intrinsic apoptotic signaling pathway in response to endoplasmic reticulum stress / signal transduction in response to DNA damage / forebrain development / cardiac muscle cell apoptotic process / enzyme activator activity / cellular response to transforming growth factor beta stimulus / heat shock protein binding / intrinsic apoptotic signaling pathway / cellular response to dexamethasone stimulus / response to nutrient / kidney development / neural tube closure / response to ischemia / positive regulation of apoptotic signaling pathway / NOD1/2 Signaling Pathway / mitochondrial intermembrane space / protein processing / ADP binding / SH3 domain binding / activation of cysteine-type endopeptidase activity involved in apoptotic process / intrinsic apoptotic signaling pathway in response to DNA damage / cellular response to UV / positive regulation of neuron apoptotic process / response to estradiol / nervous system development / peptidase activity / regulation of apoptotic process / secretory granule lumen / neuron apoptotic process / ficolin-1-rich granule lumen / response to lipopolysaccharide / electron transfer activity / cell differentiation / response to hypoxia / positive regulation of apoptotic process / cysteine-type endopeptidase activity / nucleotide binding / lipid binding / apoptotic process / DNA damage response / heme binding / Neutrophil degranulation / protein kinase binding / protein-containing complex / mitochondrion / proteolysis / extracellular exosome / extracellular region / ATP binding / identical protein binding / nucleus / metal ion binding / cytoplasm / cytosol 類似検索 - 分子機能
ジャーナル: Proc Natl Acad Sci U S A / 年: 2017 タイトル: Mechanistic insights into caspase-9 activation by the structure of the apoptosome holoenzyme. 著者: Yini Li / Mengying Zhou / Qi Hu / Xiao-Chen Bai / Weiyun Huang / Sjors H W Scheres / Yigong Shi / 要旨: Mammalian intrinsic apoptosis requires activation of the initiator caspase-9, which then cleaves and activates the effector caspases to execute cell killing. The heptameric Apaf-1 apoptosome is ...Mammalian intrinsic apoptosis requires activation of the initiator caspase-9, which then cleaves and activates the effector caspases to execute cell killing. The heptameric Apaf-1 apoptosome is indispensable for caspase-9 activation by together forming a holoenzyme. The molecular mechanism of caspase-9 activation remains largely enigmatic. Here, we report the cryoelectron microscopy (cryo-EM) structure of an apoptotic holoenzyme and structure-guided biochemical analyses. The caspase recruitment domains (CARDs) of Apaf-1 and caspase-9 assemble in two different ways: a 4:4 complex docks onto the central hub of the apoptosome, and a 2:1 complex binds the periphery of the central hub. The interface between the CARD complex and the central hub is required for caspase-9 activation within the holoenzyme. Unexpectedly, the CARD of free caspase-9 strongly inhibits its proteolytic activity. These structural and biochemical findings demonstrate that the apoptosome activates caspase-9 at least in part through sequestration of the inhibitory CARD domain.