Stewart Alan J, Morgan Kevin, Farquharson Colin, Millar Robert P
MRC Human Reproductive Sciences Unit, Centre for Reproductive Biology, The Queen's Medical Research Institute, Edinburgh, UK.
Neuroendocrinology. 2007;86(4):243-8. doi: 10.1159/000107795. Epub 2007 Aug 30.
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.
磷脂酰肌醇特异性磷脂酶C（PLC）是肌醇脂质信号通路的核心，促进细胞内钙离子释放和蛋白激酶C激活。最近在哺乳动物中发现了具有新型结构域结构的第六类磷脂酰肌醇特异性PLC，即PLC-η（PLCη）。本文综述的最新研究表明，该类由两种酶组成，即PLCη1和PLCη2。这两种酶都能水解磷脂酰肌醇4,5-二磷酸，并且比其他PLC同工酶对钙离子更敏感，可能介导G蛋白偶联受体（GPCR）信号通路。这两种酶都在富含神经元的区域表达，在大脑中含量丰富。我们证明它们也在神经内分泌细胞系中表达。因此，PLCη酶代表了影响大脑和神经内分泌系统中细胞内钙离子动态和蛋白激酶C激活的新型蛋白质，作为GPCR调节的假定介质。
