CHARACTERIZATION AND CHROMOSOMAL LOCALIZATION OF THE GENE FOR HUMAN RHODOPSIN KINASE

G-protein-dependent receptor kinases (GRKs) play a key role in the ada ptation of receptors to persistent stimuli. In rod photoreceptors rhod opsin kinase (RK) mediates rapid desensitization of rod photoreceptors to light by catalyzing phosphorylation of the visual pigment rhodopsi n. To study the structure and mechanism of GRKs in human photoreceptor s, we have isolated and characterized cDNA and genomic clones derived from the human RK locus using a bovine rhodopsin kinase cDNA fragment as a probe. The RK locus, assigned to chromosome 13 band q34, is compo sed of seven exons that encode a protein 92% identical in amino acid s equence to bovine rhodopsin kinase. The marked difference between the structure of this gene and that of another recently cloned human GRK g ene suggests the existence of a wide evolutionary gap between members of the GRK gene family. (C) 1996 Academic Press, Inc.