Phospholipase C-eta enzymes as putative protein kinase C and Ca2+ signalling components in neuronal and neuroendocrine tissues.
Phosphoinositol-specific phospholipase C enzymes (PLCs) are central to inositol lipid signalling pathways, facilitating intracellular Ca2+ release and protein kinase C activation. A sixth class of phosphoinositol-specific PLC with a novel domain structure, PLC-eta (PLCeta) has recently been discovered in mammals. Recent research, reviewed here, shows that this class consists of two enzymes, PLCeta1 and PLCeta2. Both enzymes hydrolyze phosphatidylinositol 4,5-bisphosphate and are more sensitive to Ca2+ than other PLC isozymes and are likely to mediate G-protein-coupled receptor (GPCR) signalling pathways. Both enzymes are expressed in neuron-enriched regions, being abundant in the brain. We demonstrate that they are also expressed in neuroendocrine cell lines. PLCeta enzymes therefore represent novel proteins influencing intracellular Ca2+ dynamics and protein kinase C activation in the brain and neuroendocrine systems as putative mediation of GPCR regulation.
Stewart
Alan J
AJ
MRC Human Reproductive Sciences Unit, Centre for Reproductive Biology, The Queen's Medical Research Institute, Edinburgh, UK. A.Stewart@hrsu.mrc.ac.uk
Morgan
Kevin
K
Farquharson
Colin
C
Millar
Robert P
RP
D000818:Animals; D020013:Calcium Signaling / Q000235:genetics / Q000502:physiology*; D006801:Humans; D009474:Neurons / Q000201:enzymology* / Q000502:physiology; D009490:Neurosecretory Systems / Q000166:cytology / Q000201:enzymology* / Q000502:physiology; D054801:Phosphoinositide Phospholipase C / Q000235:genetics / Q000502:physiology*; D011493:Protein Kinase C / Q000235:genetics / Q000502:physiology*
D011493:Protein Kinase C; C506060:PLCH1 protein, human; D054801:Phosphoinositide Phospholipase C