title: Src homology domains in phospholipase C-gamma1 mediate its anti-apoptotic action through regulating the enzymatic activity.
abstract: Phospholipase-gamma1 (PLC-gamma1) prevents programmed cell death, for which the enzymatic activity has been implicated. However, the biological function of Src homology (SH) domains of PLC-gamma1 in promoting cell survival remains elusive. Here, we showed that deletion of the N-SH2 domain or both N-SH2 and C-SH2 domains, but not the SH3 domain, abolished the anti-apoptotic activity of PLC-gamma1. Surprisingly, removal of the whole SH domain inhibited apoptosis. The lipase-inactive PLC-gamma1 mutant (LIM) failed to suppress apoptosis. Moreover, the phospholipase activity in SH3- or whole SH domain-deleted cells was comparable to that of wild-type cells. By contrast, the enzymatic activity was substantially ablated in SH2 domain-deleted or LIM cells. A pharmacological inhibitor of PLC-gamma1 robustly diminished the anti-apoptotic action in wild-type, SH3- or whole SH domain-deleted cells, whereas pretreatment of SH2 domain-deleted or LIM cells with agents activating PKC and calcium mobilization markedly promoted cell survival. These results indicate that SH domains in PLC-gamma1 might mediate its anti-apoptotic action by regulating the enzymatic activity.
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
authors.forename: Keqiang
authors.initials: K
authors.lastname: Ye
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D015153:Blotting, Western / Q000379:methods; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D053938:DNA Fragmentation / Q000502:physiology; D004347:Drug Interactions; D004963:Estrenes / Q000494:pharmacology; D007211:Indoles / Q000378:metabolism; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D016296:Mutagenesis / Q000502:physiology; D020932:Nerve Growth Factor / Q000494:pharmacology; D016716:PC12 Cells; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D051966:Phospholipase C gamma; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D014162:Transfection / Q000379:methods; D010738:Type C Phospholipases / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D018909:src Homology Domains / Q000502:physiology*
chemical_list: D004963:Estrenes; D007211:Indoles; D007476:Ionophores; D010726:Phosphodiesterase Inhibitors; D011725:Pyridines; D011760:Pyrrolidinones; C431843:tris(2-pyridylmethyl)amine; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C074854:U 73343; C007293:DAPI; D015759:Ionomycin; D020932:Nerve Growth Factor; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases