Structure and function of the visual arrestin oligomer. EMBO J 2007 Mar 21;26(6):1726-36
Date
03/03/2007Pubmed ID
17332750Pubmed Central ID
PMC1829381DOI
10.1038/sj.emboj.7601614Scopus ID
2-s2.0-33947577189 (requires institutional sign-in at Scopus site) 101 CitationsAbstract
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.
Author List
Hanson SM, Van Eps N, Francis DJ, Altenbach C, Vishnivetskiy SA, Arshavsky VY, Klug CS, Hubbell WL, Gurevich VVAuthor
Candice S. Klug PhD Professor in the Biophysics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsArrestin
Cattle
Crystallization
Humans
Light
Magnetic Resonance Spectroscopy
Microtubules
Models, Molecular
Mutagenesis, Site-Directed
Oligodeoxyribonucleotides
Phosphorylation
Protein Binding
Rhodopsin
Scattering, Radiation