Premium
Structure and function of the visual arrestin oligomer
Author(s) -
Hanson Susan M,
Van Eps Ned,
Francis Derek J,
Altenbach Christian,
Vishnivetskiy Sergey A,
Arshavsky Vadim Y,
Klug Candice S,
Hubbell Wayne L,
Gurevich Vsevolod V
Publication year - 2007
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601614
Subject(s) - biology , oligomer , function (biology) , arrestin , computational biology , microbiology and biotechnology , signal transduction , materials science , polymer chemistry , g protein coupled receptor
A distinguishing feature of rod arrestin is its ability to form oligomers at physiological concentrations. Using visible light scattering, we show that rod arrestin forms tetramers in a cooperative manner in solution. To investigate the structure of the tetramer, a nitroxide side chain (R1) was introduced at 18 different positions. The effects of R1 on oligomer formation, EPR spectra, and inter‐spin distance measurements all show that the structures of the solution and crystal tetramers are different. Inter‐subunit distance measurements revealed that only arrestin monomer binds to light‐activated phosphorhodopsin, whereas both monomer and tetramer bind microtubules, which may serve as a default arrestin partner in dark‐adapted photoreceptors. Thus, the tetramer likely serves as a ‘storage’ form of arrestin, increasing the arrestin‐binding capacity of microtubules while readily dissociating to supply active monomer when it is needed to quench rhodopsin signaling.