A new inositol 1,4,5-trisphosphate binding protein similar to phospholipase C-delta(1)
A new inositol 1,4,5-trisphosphate binding protein similar to phospholipase C-delta(1)
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DOI：
10.1042/bj3130319
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发表时间：
1996-01-01
影响因子：
4.1
通讯作者：
Hirata, M
中科院分区：
文献类型：
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作者：
Kanematsu, T;Misumi, Y;Hirata, M
本文报道了从大鼠脑中分离纯化的两种1，4，5-三磷酸肌醇结合蛋白，分子量分别为85和130kDa;前者是磷脂酶C的δ（1）-同工酶（PLC-δ（1）），后者是一种未鉴定的新蛋白[Kanematsu，Takeya，Watanabe，Ozaki，Yoshida，古贺，Iwanaga和Hirata（1992）J.Biol.Chem.267，6518 - 6525]。在这里，我们描述了全长cDNA的130 kDa的胰岛素（1，4，5）P-3结合蛋白，编码1096个氨基酸的分离。预测的130 kDa蛋白的序列与PLC-δ（1）的序列具有38.2%的同源性。PLC-delta（1）的三个已知结构域（普列克底物蛋白同源性和推定的催化X和Y结构域）位于残基110 - 222、377 - 544和585 - 804，同源性分别为35.2%、48.2%和45.8%。然而，该蛋白对磷脂酰肌醇4，5-二磷酸和磷脂酰肌醇没有PLC活性。通过转染COS-1细胞表达的130 kDa蛋白以与从脑中纯化的分子相同的方式结合Ins（1，4，5）P-3。因此，130 kDa蛋白是一种新的与PLC-δ（1）同源的Ins（1，4，5）P-3结合蛋白，但没有催化活性。130 kDa蛋白的功能意义进行了讨论。
We have reported that two inositol 1,4,5-trisphosphate binding proteins, with molecular masses of 85 and 130 kDa, were purified from rat brain; the former protein was found to be the delta(1)-isoenzyme of phospholipase C (PLC-delta(1)) and the latter was an unidentified novel protein [Kanematsu, Takeya, Watanabe, Ozaki, Yoshida, Koga, Iwanaga and Hirata (1992) J. Biol. Chem. 267, 6518-6525]. Here we describe the isolation of the full-length cDNA for the 130 kDa Ins(1,4,5)P-3 binding protein, which encodes 1096 amino acids. The predicted sequence of the 130 kDa protein had 38.2% homology to that of PLC-delta(1). Three known domains of PLC-delta(1) (pleckstrin homology and putative catalytic X and Y domains) were located at residues 110-222, 377-544 and 585-804 with 35.2%, 48.2% and 45.8% homologies respectively. However, the protein showed no PLC activity to phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol. The 130 kDa protein expressed by transfection in COS-1 cells bound Ins(1,4,5)P-3 in the same way as the molecule purified from brain. Thus the 130 kDa protein is a novel Ins(1,4,5)P-3 binding protein homologous to PLC-delta(1), but with no catalytic activity. The functional significance of the 130 kDa protein is discussed.