Visual arrestin binding to rhodopsin. Diverse functional roles of positively charged residues within the phosphorylation-recognition region of arrestin.

Gurevich VV, Benovic JL
J Biol Chem. 1995 270 (11): 6010-6

PMID: 7890732 · DOI:10.1074/jbc.270.11.6010

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 discussed.

MeSH Terms (24)

Acetates Acetic Acid Amino Acid Sequence Animals Antigens Arrestin Binding Sites Cattle Eye Proteins Humans Kinetics Molecular Sequence Data Mutagenesis, Site-Directed Phosphodiesterase Inhibitors Phosphorylation Point Mutation Protein Biosynthesis Recombinant Proteins Restriction Mapping Rhodopsin Sequence Homology, Amino Acid Signal Transduction Transcription, Genetic Vision, Ocular

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