PHOSPHATIDYLINOSITOL TRANSFER PROTEIN REQUIRED FOR ATP-DEPENDENT PRIMING OF CA2+-ACTIVATED SECRETION
PHOSPHATIDYLINOSITOL TRANSFER PROTEIN REQUIRED FOR ATP-DEPENDENT PRIMING OF CA2+-ACTIVATED SECRETION
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DOI：
10.1038/366572a0
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发表时间：
1993-12-09
期刊：
影响因子：
64.8
通讯作者：
MARTIN, TFJ
中科院分区：
文献类型：
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作者：
HAY, JC;MARTIN, TFJ
通过鉴定具有已知生化活性的参与蛋白，将有助于阐明负责分泌细胞中分泌颗粒与质膜的钙调节融合的反应。可能在钙调节分泌中起作用的胞质 1-3 和囊泡 4,5 蛋白的成功表征尚未揭示该过程背后的分子事件。调节分泌包括顺序启动和触发步骤，分别依赖于 ATP 和 Ca2+，并且需要不同的胞质蛋白6。启动特异性因子（PEP 蛋白）的表征应该能够识别需要 ATP 的反应。在这里，我们证明哺乳动物启动因子之一 (PEP3) 与磷脂酰肌醇转移蛋白 (PITP)7 相同。 PITP 的生理作用以前未知。我们还发现 SEC14p（酵母磷脂酰肌醇转移蛋白，对于组成型分泌至关重要 8-10）可以在引发中替代 PEP3/PITP。我们的结果表明，磷脂转移蛋白的作用在组成型和调节性分泌途径中是保守的。
ELUCIDATION of the reactions responsible for the calcium-regulated fusion of secretory granules with the plasma membrane in secretory cells would be facilitated by the identification of participant proteins having known biochemical activities. The successful characterization of cytosolic1-3 and vesicle 4,5 proteins that may function in calcium-regulated secretion has not yet revealed the molecular events underlying this process. Regulated secretion consists of sequential priming and triggering steps which depend on ATP and Ca2+, respectively, and require distinct cytosolic proteins6. Characterization of priming-specific factors (PEP proteins) should enable the ATP-requiring reactions to be identified. Here we show that one of the mammalian priming factors (PEP3) is identical to phosphatidylinositol transfer protein (PITP)7. The physiological role of PITP was previously unknown. We also find that SEC14p, the yeast phosphatidylinositol transfer protein which is essential for constitutive secretion8-10, can substitute for PEP3/PITP in priming. Our results indicate that a role for phospholipid transfer proteins is conserved in the constitutive and regulated secretory pathways.