Substrate recognition determinants for rhodopsin kinase: studies with synthetic peptides, polyanions, and polycations.
Substrate recognition determinants for rhodopsin kinase: studies with synthetic peptides, polyanions, and polycations.
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视紫红质激酶的底物识别决定因素：合成肽、聚阴离子和聚阳离子的研究。
DOI：
10.1021/bi00448a013
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发表时间：
1989
期刊：
影响因子：
2.9
通讯作者：
Hargrave,PA
中科院分区：
文献类型：
--
作者：
Palczewski,K;Arendt,A;McDowell,JH;Hargrave,PA
佛罗里达州 32610 收稿日期：1989 年 1 月 31 日；修订稿于 1989 年 5 月 23 日收到摘要：视紫红质激酶磷酸化来自牛视紫红质羧基末端序列的含丝氨酸和苏氨酸的肽。随着肽长度在 12-31 个氨基酸范围内增加，肽的 Km 降低，视紫红质序列中的肽 318-348 达到 1.7 mM。视紫红质磷酸化的 Km 比肽的磷酸化 Km 低约 103，这表明视紫红质激酶与其底物光解视紫红质的结合不仅仅涉及与待磷酸化的羧基末端肽区域的结合。来自包含丝氨酸和苏氨酸的视紫红质序列的合成肽通过用丝氨酸取代苏氨酸而被改进为底物，这表明丝氨酸残基是优选的底物。来自人红色或绿色视锥视色素、0-肾上腺素能受体或 Mt 毒蕈碱乙酰胆碱受体的类似 25 个氨基酸肽是比来自牛视紫红质的肽更好的牛视紫红质激酶底物。来自非受体蛋白 aslB-酪蛋白的酸性含丝氨酸肽也是视紫红质激酶的良好底物。然而，作为其他蛋白激酶（组蛋白 IIA、组蛋白 IIS、鲱鱼碱、鲑鱼碱和神经丝肽）底物的许多碱性肽不会被视紫红质激酶磷酸化。聚阳离子如精胺或亚精胺是视紫红质或其合成肽 324-348 磷酸化的非必需激活剂。聚阴离子如聚天冬氨酸、硫酸葡聚糖或聚腺苷酸会抑制激酶。聚 (L-天冬氨酸) 是视紫红质 (Kj= 300 µ) 的竞争性抑制剂，并且对 ATP 表现出混合型抑制作用。视紫红质是脊椎动物视网膜中视杆细胞的感光蛋白。作为视觉转导过程的一部分，视紫红质被特定的蛋白激酶（视紫红质激酶）磷酸化。光吸收后的磷酸化是终止激发过程的一种机制[Stryer (1986) 评论]。受体磷酸化可能是其他信号转导系统中受体失活的一般过程。已发现许多其他受体蛋白与视紫红质同源，并已被证明会发生磷酸化[由 Sibley 等人审查（1987）；多尔曼等人，1987]，
Florida 32610 Received January 31, 1989; Revised Manuscript Received May 23, 1989 abstract: Rhodopsin kinase phosphorylates serine-and threonine-containing peptides from bovine rhodopsin’s carboxyl-terminal sequence. Km's for the peptides decrease as the length of the peptide is increased over the range 12-31 amino acids, reaching 1.7 mM for peptide 318-348 from the rhodopsin sequence. The Km for phosphorylation of rhodopsin is about 103 lower than thatfor the peptides, which suggests that binding of rhodopsin kinase to its substrate, photolyzed rhodopsin, involves more than just binding to the carbox-yl-terminal peptide region that is to be phosphorylated. A synthetic peptide from the rhodopsin sequence that contains both serines and threonines is improved as a substrate by substitution of serines for the threonines, suggesting that serine residues are preferred as substrates. Analogous 25 amino acid peptides from the human red or green cone visual pigment, a 0-adrenergic receptor, or Mt muscarinic acetylcholine receptors are better substrates for bovine rhodopsin kinase than is the peptide from bovine rhodopsin. An acidic se-rine-containing peptide from a non-receptor protein, aslB-casein, is also a good substrate for rhodopsin kinase. However, many basic peptides that are substrates for other protein kinases—histone IIA, histone IIS, clupeine, salmine, and a neurofilament peptide—are not phosphorylated by rhodopsin kinase. Polycations such as spermine or spermidine are nonessential activators of phosphorylation of rhodopsin or its synthetic peptide 324-348. Polyanions such as poly (aspartic acid), dextran sulfate, or poly (adenylic acid) inhibit the kinase. Poly (L-aspartic acid) is a competitive inhibitor with respect to rhodopsin (Kj= 300 µ) and shows mixed type inhibition with respect to ATP.Rhodopsin is the photoreceptor protein of rod cells in the vertebrate retina. As part of the visual transduction process, rhodopsin becomes phosphorylated by a specific protein kinase, rhodopsin kinase. This phosphorylation following light absorption is one mechanism of terminating the excitation process [reviewed by Stryer (1986)]. Receptor phosphorylation may be a general process for receptor deactivation in other signal transduction systems. A number of otherreceptor proteins have been found to be homologous to rhodopsin and have been shown to undergo phosphorylation [reviewed by Sibley et al.(1987); Dohlman et al., 1987],