title: Identification of a novel class of mammalian phosphoinositol-specific phospholipase C enzymes.
abstract: 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.
authors.affiliation: Division of Gene Function and Development, Roslin Institute, Roslin, Midlothian EH25 9PS, UK. alan.stewart@bbsrc.ac.uk
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Stewart
authors.forename: Joy
authors.initials: J
authors.lastname: Mukherjee
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Roberts
authors.forename: Douglas
authors.initials: D
authors.lastname: Lester
authors.forename: Colin
authors.initials: C
authors.lastname: Farquharson
mesh_terms: 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
chemical_list: D012333:RNA, Messenger; D043265:Phosphatidylinositol Diacylglycerol-Lyase