Arrestin residues involved in the functional binding of arrestinto phosphorylated, photolyzed rhodopsin

[摘要] Purpose: The purpose of our study was to determine whether arrestinresidues previously predicted by computational modeling to interact withan aspartic acid substituted rhodopsin tail are actually involved ininteractions with phospho-residues on the rhodopsin cytoplasmic tail.Methods: We generated arrestin mutants with altered charges atpredicted positions. These mutants were then tested for the ability toinhibit rhodopsin using both direct binding assays, as well asfunctional assays involving transducin inhibition assays.Results: Our results demonstrate that the computer-predictedresidues are indeed involved in both the ability of the low-affinitystate of arrestin to bind to rhodopsin as well as the ability ofarrestin to be induced into a higher-affinity state in aphospho-residue-dependent manner.Conclusions: Our results also suggest that positions K14, K15, R29,H301, and K300 on arrestin interact with the phosphorylated carboxyltail of rhodopsin and that this translates to the efficient activationof arrestin.

[学科分类] 生物化学/生物物理