Asp278 of human beta-adrenergic receptor kinase 1 is essential for phosphorylation activity.
Asp278 of beta-adrenergic receptor kinase 1 (betaARK1) was suggested to play a key role in substrate recognition of beta2-adrenergic receptors in our previous study, in which a three-dimensional model of betaARK1 was studied in comparison with a crystal structure of PKA-PKI5-24 complex. In the present study, to confirm the molecular recognition mechanism at Asp278 of betaARK1, two mutants of betaARK1, D278R and D278A, were designed based on molecular modeling studies and produced by Sf-9 cells. As predicted by the molecular modeling study, the mutants showed no kinase activities while wild type betaARK1 phosphorylated beta2-adrenergic receptors in a concentration-dependent manner. These results strongly suggest the involvement of Asp278 in substrate recognition by betaARK1. The results also suggest a high reliability of the three-dimensional model of betaARK1.
Iino
M
M
Tokyo R&D Center, Daiichi Pharmaceutical Co., Ltd, Japan.
Furugohri
T
T
Fukuzawa
A
A
Shibano
T
T
D000409:Alanine / Q000235:genetics; D019943:Amino Acid Substitution / Q000235:genetics; D001120:Arginine / Q000235:genetics; D001224:Aspartic Acid / Q000235:genetics / Q000502:physiology*; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D013379:Substrate Specificity; D051552:beta-Adrenergic Receptor Kinases
D001224:Aspartic Acid; D001120:Arginine; D017868:Cyclic AMP-Dependent Protein Kinases; D051552:beta-Adrenergic Receptor Kinases; D000409:Alanine