Ca(2+)-dependent interaction of recoverin with rhodopsin kinase

J Biol Chem. 1995 Jul 28;270(30):18060-6. doi: 10.1074/jbc.270.30.18060.


Recoverin (Rv) is a myristoylated Ca(2+)-binding protein present primarily in bovine photoreceptors. It represents a newly identified family of neuronal specific Ca(2+)-binding proteins that includes neurocalcin, hippocalcin, and guanylyl cyclase-activating protein. To investigate the function of Rv in photoreceptors, we identified proteins that bind immobilized Rv in a Ca(2+)-dependent manner. Rhodopsin kinase (RK), interphotoreceptor retinoid-binding protein, and tubulin interact with Rv in the presence of Ca2+. The importance of the Rv/RK interaction was further characterized. RK, purified using immobilized Rv as an affinity matrix, catalyzed the light-dependent and Ca(2+)-independent incorporation of phosphates into rhodopsin when reconstituted with urea-stripped rod outer segment membranes. When only a small fraction (0.04%) of rhodopsin was photolyzed, as many as 700 phosphates were incorporated per photolyzed rhodopsin, a phenomenon known as "high gain" phosphorylation. When recoverin was added, the activity of RK became sensitive to free Ca2+, with EC50 = 3 microM. The N-terminal myristoyl residue of Rv enhances the inhibitory effect of Rv and introduces cooperativity to the Ca(2+)-dependent inhibition of rhodopsin phosphorylation. Rv neither interacts with other members of the G-protein-coupled receptor kinase family such as beta-adrenergic receptor kinase 1 nor inhibits beta-adrenergic receptor kinase 1 activity. The specific and Ca(2+)-dependent Rv/RK interaction is necessary for the inhibitory effect of Rv on rhodopsin phosphorylation and may play an important role in photoreceptor light adaptation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium / metabolism*
  • Calcium-Binding Proteins / metabolism*
  • Catalysis
  • Cattle
  • Chromatography, Affinity
  • Eye Proteins*
  • G-Protein-Coupled Receptor Kinase 1
  • Hippocalcin
  • Lipoproteins*
  • Molecular Sequence Data
  • Nerve Tissue Proteins*
  • Phosphorylation
  • Photoreceptor Cells / enzymology
  • Photoreceptor Cells / metabolism
  • Protein Kinase Inhibitors
  • Protein Kinases / isolation & purification
  • Protein Kinases / metabolism*
  • Recoverin
  • Rod Cell Outer Segment / enzymology
  • Urea / chemistry


  • Calcium-Binding Proteins
  • Eye Proteins
  • Lipoproteins
  • Nerve Tissue Proteins
  • Protein Kinase Inhibitors
  • Recoverin
  • Hippocalcin
  • Urea
  • Protein Kinases
  • G-Protein-Coupled Receptor Kinase 1
  • Calcium