InterPro domain: IPR024253

The outer and inner segments of vertebrate rod photoreceptor cells contain phosducin, a soluble phosphoprotein that complexes with the beta/gamma-subunits of the GTP-binding protein, transducin. Light-induced changes in cyclic nucleotide levels modulate the phosphorylation of phosducin by protein kinase A [ 1 ]. The protein is thought to participate in the regulation of visual phototransduction or in the integration of photo-receptor metabolism. Similar proteins have been isolated from the pineal gland and it is believed that the functional role of the protein is the same in both retina and pineal gland [ 2 ].

This entry represents a domain found in members of the phosducin family. This domain has a thioredoxin-like fold [ 3 ].

1. Amino acid and cDNA sequence of bovine phosducin, a soluble phosphoprotein from photoreceptor cells. J. Biol. Chem. 265, 15867-73
2. Analysis of the human, bovine and rat 33-kDa proteins and cDNA in retina and pineal gland. Gene 91, 209-15
3. Structure of the thioredoxin-fold domain of human phosducin-like protein 2. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 65, 67-70