Autophosphorylation of inositol 1,4,5-trisphosphate receptors.
Autophosphorylation of inositol 1,4,5-trisphosphate receptors.
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DOI：
10.1016/s0021-9258(19)50532-4
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发表时间：
1992-04
期刊：
影响因子：
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通讯作者：
C. D. Ferris;A. Cameron;D. Bredt;R. Huganir;S. Snyder
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文献类型：
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作者：
C. D. Ferris;A. Cameron;D. Bredt;R. Huganir;S. Snyder
肌醇1，4，5-三磷酸(IP3)通过与包括IP3识别位点和相关钙通道在内的特定膜受体结合，释放体内储存的钙离子。IP3受体受三磷酸腺苷、钙、蛋白激酶A、蛋白激酶C和钙/钙调蛋白依赖的蛋白激酶II的磷酸化调控。其cDNA序列预测了至少两个核苷酸可能结合的共同序列，并且已经证实了三磷酸腺苷与IP3受体的直接结合。在本研究中，我们证明了纯化和重组的IP3受体在丝氨酸上的自磷酸化作用，并发现IP3受体对特定的多肽底物具有丝氨酸蛋白激酶活性。几个独立的纯化程序不能将IP3受体蛋白从磷酸化活性中分离出来，许多不同的蛋白激酶激活剂和抑制剂也不能将蛋白激酶识别为污染物。此外，复性实验还显示聚偏二氟乙烯膜上的单体受体发生了自磷酸化。
Inositol 1,4,5-trisphosphate (IP3) releases internal stores of calcium by binding to a specific membrane receptor which includes both the IP3 recognition site as well as the associated calcium channel. The IP3 receptor is regulated by ATP, calcium, and phosphorylation by protein kinase A, protein kinase C, and calcium/calmodulin-dependent protein kinase II. Its cDNA sequence predicts at least two consensus sequences where nucleotides might bind, and direct binding of ATP to the IP3 receptor has been demonstrated. In the present study, we demonstrate autophosphorylation of the purified and reconstituted IP3 receptor on serine and find serine protein kinase activity of the IP3 receptor toward a specific peptide substrate. Several independent purification procedures do not separate the IP3 receptor protein from the phosphorylating activity, and many different protein kinase activators and inhibitors do not identify protein kinases as contaminants. Also, renaturation experiments reveal autophosphorylation of the monomeric receptor on polyvinylidene difluoride membranes.