TWO NOVEL CPLA2 BINDING PROTEINS AND CELL DEATH

描述（改编自研究者摘要）：细胞溶质 磷脂酶A2（cPLA 2）与细胞损伤有关，然而， cPLA 2的作用机制尚不清楚。cPLA 2定位于 核内位点对血清剥夺的反应导致细胞 死亡两个新的核cPLA 2相互作用蛋白已被分离。 这些cPLA 2相互作用子与酵母沉默基因SIR 2同源 SAS 2/SAS 3。这些相互作用的蛋白质之一，PLIP，（用于 磷脂酶A2相互作用蛋白），具有氨基酸序列 包含最近描述的MYST结构域。MYST域名由 一种非典型的C2 HC锌指和一种标志性的乙酰转移酶 顺序该结构域的存在以及PLIP与酵母的同源性 果蝇和哺乳动物的蛋白质表明， PLIP和cPLA 2的转录调控。的表达 PLIP在肾小球系膜细胞中显著增强细胞损伤， 血清剥夺和TNF α。很可能是核内的 含有cPLA 2和两种相互作用蛋白的复合物介导了 系膜细胞对TNF α和血清剥夺的反应。第一 这项建议的目的是研究PLIP调节的机制， cPLA 2活性，并有助于系膜细胞对 损伤第二个具体目的是表征第二克隆46， 确定其在cPLA 2调节中的作用，并确定其作用，如果 细胞对损伤的敏感性。为了实现这些目标，基本 分子生物学、细胞和脂质生物化学技术将 具体包括定点诱变和 腺病毒表达系统。转染的构建体编码 过氧化物酶体增殖物激活受体（过氧化物酶体增殖物激活受体），并含有 由PPAR应答元件驱动的报告基因将用于 核内花生四烯酸释放的功能读数。的 这项建议的完成将大大提高我们对 cPLA 2在细胞损伤中的作用及其调节。

DESCRIPTION (Adapted from Investigator's Abstract): Cytosolic phospholipase A2 (cPLA2) has been implicated in cell injury, however, the mechanisms by which cPLA2 acts are unknown. cPLA2 localizes to an intranuclear site in response to serum deprivation resulting in cell death. Two novel nuclear cPLA2-interacting proteins have been isolated. These cPLA2-interactors are homologous to yeast silencing genes, SIR2 and SAS2/SAS3. One of these interacting proteins, PLIP, (for Phospholipase A2-interacting protein), has an amino acid sequence containing a recently described MYST domain. The MYST domain is made up of an atypical C2HC zinc finger and a signature acetyltransferase sequence. The presence of this domain and homologies of PLIP to yeast drosophila and mammalian proteins suggest a potential role in transcriptional regulation for PLIP and thus cPLA2. The expression of PLIP in renal mesangial cells markedly enhances cell injury due to both serum deprivation and TNFalpha. It is likely that an intranuclear complex containing cPLA2 and the two interactor proteins mediates the mesangial cell response to TNFalpha and to serum deprivation. The first aim of this proposal is to examine mechanisms by which PLIP modulates cPLA2 activity and contributes to mesangial cell susceptibility to injury. The second specific aim is to characterize the second clone 46, to identify its role in cPLA2 regulation, and to determine its role, if any, in cell susceptibility to injury. To achieve these aims, basic techniques in molecular biology and cellular and lipid biochemistry will be used, specifically including site directed mutagenesis and an adenoviral expression system. Transfected constructs encoding a peroxosomal proliferator activated receptor (PPAR) and containing a reporter gene driven by a PPAR response element will be used for a functional readout of intranuclear arachidonic acid release. The completion of this proposal will greatly enhance our understanding of the role and regulation of cPLA2 in cell injury.