3h11
Zymogen caspase-8:c-FLIPL protease domain complexZymogen caspase-8:c-FLIPL protease domain complex
Structural highlights
FunctionCFLAR_HUMAN Apoptosis regulator protein which may function as a crucial link between cell survival and cell death pathways in mammalian cells. Acts as an inhibitor of TNFRSF6 mediated apoptosis. A proteolytic fragment (p43) is likely retained in the death-inducing signaling complex (DISC) thereby blocking further recruitment and processing of caspase-8 at the complex. Full length and shorter isoforms have been shown either to induce apoptosis or to reduce TNFRSF-triggered apoptosis. Lacks enzymatic (caspase) activity.[1] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCellular FLICE-inhibitory protein (c-FLIP(L)) is a key regulator of the extrinsic cell death pathway. Although widely regarded as an inhibitor of initiator caspase activation and cell death, c-FLIP(L) is also capable of enhancing procaspase-8 activation through heterodimerization of their respective protease domains. However, the underlying mechanism of this activation process remains enigmatic. Here, we demonstrate that cleavage of the intersubunit linker of c-FLIP(L) by procaspase-8 potentiates the activation process by enhancing heterodimerization between the two proteins and vastly improving the proteolytic activity of unprocessed caspase-(C)8. The crystal structures of the protease-like domain of c-FLIP(L) alone and in complex with zymogen C8 identify the unique determinants that favor heterodimerization over procaspase-8 homodimerization, and induce the latent active site of zymogen C8 into a productive conformation. Together, these findings provide molecular insights into a key aspect of c-FLIP(L) function that modulates procaspase-8 activation to elicit diverse responses in different cellular contexts. Mechanism of procaspase-8 activation by c-FLIPL.,Yu JW, Jeffrey PD, Shi Y Proc Natl Acad Sci U S A. 2009 May 4. PMID:19416807[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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