Human substance P receptor undergoes agonist-dependent phosphorylation by G protein-coupled receptor kinase 5 in vitro.
G protein-coupled receptor kinases (GRKs) phosphorylate agonist-occupied G protein-coupled receptors, leading to receptor desensitization. Seven GRKs, designated GRK1 through 7, have been characterized. GRK5 is negatively regulated by protein kinase C. We investigated whether human substance P receptor (hSPR) is a substrate of GRK5. We report that membrane-bound hSPR is phosphorylated by purified GRK5, and that both the rate and extent of phosphorylation increase dramatically in the presence of substance P. The phosphorylation has a high stoichiometry (20+/-4 mol phosphate/mol hSPR) and a low K(m) (1.7+/-0.1 nM). These data provide the first evidence that hSPR is a substrate of GRK5.
Warabi
Kengo
K
Department of Anesthesiology, Juntendo University, Tokyo, Japan.
Richardson
Mark D
MD
Barry
William T
WT
Yamaguchi
Keisuke
K
Roush
Eric D
ED
Nishimura
Kinya
K
Kwatra
Madan M
MM
D000595:Amino Acid Sequence; D000818:Animals; D002384:Catalysis; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D054774:G-Protein-Coupled Receptor Kinase 5; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D018040:Receptors, Neurokinin-1 / Q000819:agonists / Q000378:metabolism*; D018411:Spodoptera; D013373:Substance P / Q000378:metabolism*; D013379:Substrate Specificity
D018040:Receptors, Neurokinin-1; D013373:Substance P; D017346:Protein Serine-Threonine Kinases; D054774:G-Protein-Coupled Receptor Kinase 5; C517898:GRK5 protein, human; D019204:GTP-Binding Proteins