A role for hydrolysis of inositol 1,4,5-trisphosphate in terminating the response to inositol 1,4,5-trisphosphate and to a flash of light in Limulus ventral photoreceptors.
A role for hydrolysis of inositol 1,4,5-trisphosphate in terminating the response to inositol 1,4,5-trisphosphate and to a flash of light in Limulus ventral photoreceptors.
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肌醇 1,4,5-三磷酸水解在终止鲎腹侧光感受器对肌醇 1,4,5-三磷酸和闪光的反应中的作用。
DOI：
10.1016/s0006-8993(97)00603-3
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发表时间：
1997
期刊：
影响因子：
2.9
通讯作者：
Fein,A
中科院分区：
文献类型：
--
作者：
Vallet,AM;Fein,A
将肌醇1，4，5-三磷酸(INS-1，4，5-P3)注射到示踪腹侧光感受器，产生类似于光产生的兴奋。一个可能有助于快速终止对INS 1，4，5-P3和光的反应的过程是INS 1，4，5-P3被InsP3-5-磷酸酶水解形成1，4-二磷酸肌醇。已知的肌醇2，4，5-三磷酸(INS 2，4，5-P3)比INS 1，4，5-P3更难被InsP3-5-磷酸酶水解。腹侧光感受器对注射INS 1，4，5-P3的反应是单波去极化，而对INS 2，4，5-P3的反应是一连串的去极化波。我们的假说是InsP3-5-磷酸酶对水解的抵抗导致了INS-2，4，5-P3产生的波的爆发。为了测试这一想法，我们在含有非特异性磷酸酶抑制剂的情况下向腹侧光感受器注射INS 1，4，5-P3，钒酸盐和氟化物，这会延长腹侧光感受器对闪光的反应(D.W.Corson，A.Fein，W.W.Walthall，J.Gen.Physiol)。82(1983)659-677)。在氟化物或钒酸盐存在下，对Ins-1，4，5-P3的反应是由一连串的波组成，而不是单一的去极化波。结论：InsP3-5-磷酸酶对INS-1，4，5-P3的降解在终止腹侧光感受器对INS-1，4，5-P3和光的反应中起着重要作用。
Injection of inositol 1,4,5-trisphosphate (Ins 1,4,5-P3) into Limulus ventral photoreceptors produces excitation similar to that produced by light. One process which might contribute to rapid termination of the responses to Ins 1,4,5-P3and to light is the hydrolysis of Ins 1,4,5-P3by an InsP3-5-phosphatase to form inositol 1,4-bisphosphate. Inositol 2,4,5-trisphosphate (Ins 2,4,5-P3) is known to be less hydrolysable by the InsP3-5-phosphatase than is Ins 1,4,5-P3. Whereas ventral photoreceptors respond to an injection of Ins 1,4,5-P3with a single wave of depolarization, the response to Ins 2,4,5-P3is a burst of waves of depolarization. Our hypothesis is that it is the resistance to hydrolysis by the InsP3-5-phosphatase which accounts for the burst of waves produced by Ins 2,4,5-P3. To test this idea we injected ventral photoreceptors with Ins 1,4,5-P3in the presence of the non-specific phosphatase inhibitors, vanadate and fluoride, which prolong the response to a flash of light in ventral photoreceptors (D.W. Corson, A. Fein, W.W. Walthall, J. Gen. Physiol. 82 (1983) 659–677). In the presence of fluoride or vanadate the response to Ins 1,4,5-P3was composed of a burst of waves rather than a single wave of depolarization. We conclude that hydrolysis of Ins 1,4,5-P3by the InsP3-5-phosphatase plays a role in terminating the ventral photoreceptors response to Ins 1,4,5-P3and also to light.