X-ray crystal structure of arrestin from bovine rod outer segments

Abstract

Retinal arrestin is the essential protein for the termination of the light response in vertebrate rod outer segments. It plays an important role in quenching the light-induced enzyme cascade by its ability to bind to phosphorylated light-activated rhodopsin (P-Rh*). Arrestins are found in various G-protein-coupled amplification cascades. Here we report on the three-dimensional structure of bovine arrestin (relative molecular mass, 45,300) at 3.3 A resolution. The crystal structure comprises two domains of antiparallel beta-sheets connected through a hinge region and one short alpha-helix on the back of the amino-terminal fold. The binding region for phosphorylated light-activated rhodopsin is located at the N-terminal domain, as indicated by the docking of the photoreceptor to the three-dimensional structure of arrestin. This agrees with the interpretation of binding studies on partially digested and mutated arrestin.

Structure and Function of the Third Intracellular Loop of the 5‐Hydroxytryptamine2A Receptor: The Third Intracellular Loop Is α‐Helical and Binds Purified Arrestins

“…We discovered several sequences that had homologies for p-arrestin. It is interesting that several of the sequences appear to be in the putative receptor interaction domain of v-arrestin (Granzin et al, 1998). To test the possibility that one of the functions of the i3 loop is to bind arrestins, we incubated purified arrestins with an i3-GST fusion protein and discovered that v-arrestin, p-arrestin, and arrestin-3 all specifically bound to the i3 loop.…”

“…It is interesting that several of these arrestin sequences identified are in the putative interaction domain where arrestins are thought to bind to GPCRs (Granzin et al, 1998).…”

β-arrestin 2 oligomerization controls the Mdm2-dependent inhibition of p53

“…Early structural studies conducted on ␤-arr1 and arrestin, found exclusively in visual tissues, reported the existence of oligomers in crystals, indicating that this family of proteins may have the propensity to form oligomers (13)(14)(15). However, the existence of constitutive oligomers in living cells at physiological concentrations was only recently confirmed (16).…”

Squid visual arrestin: cDNA cloning and calcium‐dependent phosphorylation by rhodopsin kinase (SQRK)

“…In support of this work, five fingerprint regions or motifs have been identified by the protein fingerprint database, PRINTS, within vertebrate arrestins (Granzin et al 1998).…”

“…The predicted molecular weight of the cDNA encoding squid arrestin is approximately 45 kDa and corresponds well with the estimated size (48 kDa) of the arrestin doublet identified in the squid eye and in rhabdomeric membranes on SDS polyacrylamide gels. The X-ray crystal structure of vertebrate visual arrestin has been resolved (Granzin et al 1998;Hirsch et al 1999) and a polar core composed of Asp,30 Asp296, Asp303, Arg175 and Arg382 (Vishnivetskiy et al 1999) has been identified between the N-and C-terminal domains of arrestin. Corresponding polar residues Asp26, Asn293, Asp300, Arg169 and Arg381 were identified within the squid arrestin sequence.…”