One of the Ca2+ binding sites of recoverin exclusively controls interaction with rhodopsin kinase.
Recoverin is a neuronal calcium sensor protein that controls the activity of rhodopsin kinase in a Ca(2+)-dependent manner. Mutations in the EF-hand Ca2+ binding sites are valuable tools for investigating the functional properties of recoverin. In the recoverin mutant E121Q (Rec E121Q ) the high-affinity Ca2+ binding site is disabled. The non-myristoylated form of Rec E121Q binds one Ca2+ via its second Ca(2+)-binding site (EF-hand 2), whereas the myristoylated variant does not bind Ca2+ at all. Binding of Ca2+ to non-myristoylated Rec E121Q apparently triggers exposure of apolar side chains, allowing for association with hydrophobic matrices. Likewise, an interaction surface for the recoverin target rhodopsin kinase is constituted upon Ca2+ binding to the non-acylated mutant. Structural changes resulting from Ca(2+)-occupation of EF-hand 2 in myristoylated and non-myristoylated recoverin variants are discussed in terms of critical conditions required for biological activity.
Komolov
Konstantin E
KE
Institut für Biologische Informationsverarbeitung 1, Forschungszentrum Jülich, D-52425 Jülich, Germany.
Zinchenko
Dimitri V
DV
Churumova
Valeriya A
VA
Vaganova
Svetlana A
SA
Weiergräber
Oliver H
OH
Senin
Ivan I
II
Philippov
Pavel P
PP
Koch
Karl-Wilhelm
KW
D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D005136:Eye Proteins / Q000737:chemistry / Q000378:metabolism*; D051606:G-Protein-Coupled Receptor Kinase 1; D008074:Lipoproteins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010766:Phosphorylation; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D051603:Recoverin; D012374:Rod Cell Outer Segment / Q000378:metabolism; D014508:Urea
D002135:Calcium-Binding Proteins; D005136:Eye Proteins; D008074:Lipoproteins; D051603:Recoverin; D014508:Urea; D011494:Protein Kinases; D051606:G-Protein-Coupled Receptor Kinase 1; D002118:Calcium