1. Identification of a novel class of mammalian phosphoinositol-specific phospholipase C enzymes
- Author
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Douglas H. Lester, Scott J. Roberts, Colin Farquharson, Alan J. Stewart, and Joy Mukherjee
- Subjects
chemistry.chemical_classification ,Receptor-Mediated Signaling ,Phospholipase C ,Ca2+ Signaling ,Sequence alignment ,General Medicine ,Lipid signaling ,Biology ,Isozyme ,QP ,Enzyme ,chemistry ,Biochemistry ,Phosphoinositide phospholipase C ,Genetics ,Signal transduction ,Phosphatidylinositol ,Protein kinase C ,Phospholipase C-eta ,Protein Kinase C ,Signal Transduction - 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. Publisher PDF