4qj5 | pdb_00004qj5
Structure of a fragment of human phospholipase C-beta3 delta472-581, bound to IP3 and in complex with Galphaq
Structural highlights
FunctionGNAQ_MOUSE Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. Regulates B-cell selection and survival and is required to prevent B-cell-dependent autoimmunity. Regulates chemotaxis of BM-derived neutrophils and dendritic cells (in vitro).[1] [2] Publication Abstract from PubMedPhospholipase C beta (PLCbeta) enzymes are dramatically activated by heterotrimeric G proteins. Central to this response is the robust autoinhibition of PLCbeta by the X-Y linker region within its catalytic core and by the Halpha2' helix in the C-terminal extension of the enzyme. The molecular mechanism of each and their mutual dependence are poorly understood. Herein, it is shown that distinct regions within the X-Y linker have specific roles in regulating activity. Most important, an acidic stretch within the linker stabilizes a lid that occludes the active site, consistent with crystal structures of variants lacking this region. Inhibition by the Halpha2' helix is independent of the X-Y linker and likely regulates activity by limiting membrane interaction of the catalytic core. Full activation of PLCbeta thus requires multiple independent molecular events induced by membrane association of the catalytic core and by the binding of regulatory proteins. Molecular Mechanisms of Phospholipase C beta3 Autoinhibition.,Lyon AM, Begley JA, Manett TD, Tesmer JJ Structure. 2014 Nov 25. pii: S0969-2126(14)00335-9. doi:, 10.1016/j.str.2014.10.008. PMID:25435326[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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