Identification of a novel class of mammalian phosphoinositol-specific phospholipase C enzymes.
Phosphoinositol (PhoIns)-specific phospholipase C enzymes (PLCs) are central to the inositol lipid signaling pathways and contribute to intracellular Ca2+ release and protein kinase C activation. Five distinct classes of PhoIns-specific PLCs are known to exist in mammals, which are activated by membrane receptor-mediated events. Here we have identified a sixth class of PhoIns-specific PLC with a novel domain structure, which we have termed PLC-eta. Two putative PLC-eta enzymes were identified in humans and in mice. Sequence analysis revealed that residues implicated in substrate binding and catalysis from other PhoIns-specific PLCs are conserved in the novel enzymes. PLC-eta enzymes are most closely related to the PLC-delta class and share a close evolutionary relationship with other PLC isozymes. EST analysis and RT-PCR data suggest that PLC-eta enzymes are expressed in several cell types and, by analogy with other mammalian PhoIns-specific PLCs, are likely to be involved in signal transduction pathways.
Stewart
Alan J
AJ
Division of Gene Function and Development, Roslin Institute, Roslin, Midlothian EH25 9PS, UK. alan.stewart@bbsrc.ac.uk
Mukherjee
Joy
J
Roberts
Scott J
SJ
Lester
Douglas
D
Farquharson
Colin
C
D000595:Amino Acid Sequence; D000818:Animals; D020869:Gene Expression Profiling; D006801:Humans; D008322:Mammals; D051379:Mice; D008969:Molecular Sequence Data; D043265:Phosphatidylinositol Diacylglycerol-Lyase / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D012333:RNA, Messenger; D043265:Phosphatidylinositol Diacylglycerol-Lyase