VISUAL ARRESTIN BINDING TO RHODOPSIN - DIVERSE FUNCTIONAL ROLES OF POSITIVELY CHARGED RESIDUES WITHIN THE PHOSPHORYLATION-RECOGNITION REGION OF ARRESTIN
VISUAL ARRESTIN BINDING TO RHODOPSIN - DIVERSE FUNCTIONAL ROLES OF POSITIVELY CHARGED RESIDUES WITHIN THE PHOSPHORYLATION-RECOGNITION REGION OF ARRESTIN
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DOI：
10.1074/jbc.270.11.6010
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发表时间：
1995-03-17
影响因子：
4.8
通讯作者：
BENOVIC, JL
中科院分区：
文献类型：
--
作者：
GUREVICH, VV;BENOVIC, JL
Arrestin通过与视紫质受体视紫红质的磷酸化光激活形式特异地相互作用，在猝灭光传导中起着关键作用。为了确定与视紫红质的磷酸化C末端相互作用所涉及的残基，我们将点突变引入到视觉精蛋白中先前与磷酸化识别有关的一个基本区域(残基163-189)。总共进行了9个点突变，每个点突变都用中性亲水残基取代了带正电荷的Lys、Arg或His。然后通过比较全长和截短的野生型和突变型arrestin与各种功能形式的视紫红质的结合来分析这些突变的功能后果。这些研究表明，牛Arrestin中的Arg-171、Arg-175和Lys-176在磷酸盐相互作用中起主要作用，而Lys-166和Lys-167可能在磷酸盐结合中起次要作用。相反，Lys-163和His-179似乎发挥了调节作用，而Arg-182和Arg-189并不直接参与arrestin与视紫红质的结合，而Arg-175似乎也是一个磷酸化敏感的触发器，因为通过诱变的电荷中和使arrestin-R175N能够与光激活的视紫红质结合，而野生型arrestin与磷酸化的光激活的视紫红质结合。这些发现对于arrestin与视紫红质的顺序多位点结合的意义进行了讨论。
Arrestin plays a critical role in quenching phototransduction via its ability to specifically interact with the phosphorylated light-activated form of the visual receptor rhodopsin. In an effort to identify the residues involved in interaction with the phosphorylated C terminus of rhodopsin, we introduced point mutations into a basic region in visual arrestin previously implicated in phosphorylation-recognition (residues 163-189). A total of nine point mutations were made, each substituting a neutral hydrophilic residue for a positively charged Lys, Arg, or His. The functional consequences of these mutations were then analyzed by comparing the binding of full-length and truncated wild-type and mutant arrestin to various functional forms of rhodopsin. These studies demonstrate that Arg-171, Arg-175, and Lys-176 in bovine arrestin play a primary role in phosphate interaction, while Lys-166 and Lys-167 likely play a minor role in phosphate binding. In contrast, Lys-163 and His-179 appear to play a regulatory role, while Arg-182 and Arg-189 are not directly involved in arrestin binding to rhodopsin, Arg-175 also appears to function as a phosphorylation-sensitive trigger since charge neutralization by mutagenesis enables arrestin-R175N to bind to light-activated rhodopsin as well as wild-type arrestin binds to phosphorylated light-activated rhodopsin. The implications of these findings for the sequential multisite binding of arrestin to rhodopsin are iscussed.