Asp278 of Human β-Adrenergic Receptor Kinase 1 Is Essential for Phosphorylation Activity

• Published in: Biochemical and biophysical research communications Vol. 239; no. 2; pp. 548 - 551
• Main Authors: Iino, Minoru, Furugohri, Taketoshi, Fukuzawa, Akiko, Shibano, Toshiro
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 20-10-1997
• Subjects: Alanine - genetics; Amino Acid Substitution - genetics; Arginine - genetics; Aspartic Acid - genetics; Aspartic Acid - physiology; beta-Adrenergic Receptor Kinases; Conserved Sequence; Crystallography, X-Ray; Cyclic AMP-Dependent Protein Kinases - chemistry; Cyclic AMP-Dependent Protein Kinases - genetics; Cyclic AMP-Dependent Protein Kinases - metabolism; Humans; Models, Molecular; Mutagenesis, Site-Directed; Phosphorylation; Substrate Specificity
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1997.7504

Asp278 of β-adrenergic receptor kinase 1 (βARK1) was suggested to play a key role in substrate recognition of β2-adrenergic receptors in our previous study, in which a three-dimensional model of βARK1 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 βARK1, two mutants of βARK1, 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 βARK1 phosphorylated β2-adrenergic receptors in a concentration-dependent manner. These results strongly suggest the involvement of Asp278 in substrate recognition by βARK1. The results also suggest a high reliability of the three-dimensional model of βARK1.