Intracellular calcium signals regulating cytosolic phospholipase A2 translocation to internal membranes
Intracellular calcium signals regulating cytosolic phospholipase A2 translocation to internal membranes
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DOI：
10.1074/jbc.m100943200
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发表时间：
2001-08-10
影响因子：
4.8
通讯作者：
Leslie, CC
中科院分区：
文献类型：
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作者：
Evans, JH;Spencer, DM;Leslie, CC
细胞内Ca 2+浓度（[Ca 2 +]（i））的增加促进胞浆磷脂酶A（2）（cPLA（2））向细胞内膜的转运。研究了cPLA（2）易位的特异性膜和所需的[Ca 2 +]（i）信号。将与全长cPLA（2）（EGFP-FL）或cPLA（2）C2结构域（EGFP-C2）融合的EGFP质粒用于用[Ca 2 +]（i）动员激动剂处理的细胞的C2+/EGFP成像实验。EGFP-FL，和-C2易位到高尔基体的反应，持续的[Ca 2 +]（i）大于类似于100-125 nM和高尔基体，。ER和核周膜（PNM）在[Ca 2 +]（i）大于210-280 nm。在短时间的[Ca 2 +]（i）瞬变反应中，EGFP-C2易位到高尔基体、ER和PNM，但EGFP-FL易位仅限于高尔基体。然而，EGFP-FL易位到高尔基体，ER，PNM在响应长，持续时间的瞬变。随着[Ca ~（2+）]（i）的降低，EGFP-C2容易从高尔基体上解离，但EGFPFL的解离被延迟。激动剂诱导的花生四烯酸释放与[Ca 2 +]（i）和cPLA（2）易位的程度成正比。总之，我们发现cPLA（2）向高尔基体或ER和PNM的差异易位是[Ca 2 +]（i）幅度和持续时间的函数。这些结果表明，cPLA（2），C2结构域调节差异，Ca 2+依赖性膜靶向和催化结构域调节易位率和酶的驻留。
Increased intracellular Ca2+ concentrations ([Ca2+](i)) promote cytosolic phospholipase A(2) (cPLA(2)) translocation to intracellular membranes. The specific membranes to which cPLA(2) translocates and the [Ca2+](i) signals required were investigated. Plasmids of EGFP fused to full-length cPLA(2) (EGFP-FL) or to the cPLA(2) C2 domain (EGFP-C2) were used in C2+/EGFP imaging experiments of cells treated with [Ca2+](i)-mobilizing agonists. EGFP-FL, and -C2 translocated to Golgi in response, to sustained [Ca2+](i) greater than similar to 100-125 nM and to Golgi,. ER, and perinuclear membranes (PNM) at [Ca2+](i) greater than similar to 210-280 nm. In response to short duration [Ca2+](i) transients, EGFP-C2 translocated to Golgi, ER, and PNM, but EGFP-FL translocation was restricted to Golgi. However, EGFP-FL translocated to Golgi, ER, and PNM in response to long, duration transients. In response to declining, [Ca2+](i), EGFP-C2 readily dissociated from Golgi, but EGFP FL dissociation was delayed. Agonist-induced arachidonic acid release was proportional to the [Ca2+](i) and to the extent of cPLA(2) translocation. In summary, we, find that the differential translocation of cPLA(2) to Golgi or to ER and PNM is a function of [Ca2+](i) amplitude and duration., These results suggest that the cPLA(2), C2 domain regulates differential, Ca2+-dependent membrane targeting and that the catalytic domain regulates both the rate of translocation and enzyme residence.