title: PH domain of G protein-coupled receptor kinase-2 binds to protein kinase C (PKC) and negatively regulates activity of PKC kinase.
abstract: G protein-coupled receptor kinase-2 (GRK),also known as beta1-adrenergic receptor kinase(beta-ARK1), plays an important role in agonist-induced desensitization of the beta-adrenergic receptors. Activation of protein kinase C (PKC) is able to stimulate phosphorylation and activation of GRKs and induce desensitization of G protein-coupled receptor. However, detail mechanism of interaction between PKC and GRK2 and the effect of GRK2 on activity of PKC remain unknown. Pleckstrin homology (PH) domain is a kind of functionally domain containing about 120 amino acids, which exists on many protein molecules that involve in cellular signal transduction. A PH domain located in GRK2 residue 548 to 660 may play a significant role in mediating interaction between PKC and GRK2. In present study, we revealed that PKC could associate with PH domain of GRK2 in pull-down assay in vitro. Co-immunoprecipitation displayed binding of PKC to GRK2 in intact Jurkat cells after prolonged stimulation of epinephrine. Assay of PKC beta1 kinase activity indicated that the binding of the PH domain of GRK2 to PKC beta 1 could down-regulate activity of PKC beta 1 kinase. Thus, GRK2 may play a negative feedback regulatory role on PKCbeta1 activity in interaction between GRK2 and PKCbeta 1.
authors.affiliation: Department of Biochemistry and Molecular Biology, The Fourth Military Medical University, Xi'an, Shaaxi, 710032. PR China.
authors.forename: Shaoping
authors.initials: S
authors.lastname: Ji
authors.forename: Xinping
authors.initials: X
authors.lastname: Liu
authors.forename: Shujun
authors.initials: S
authors.lastname: Li
authors.forename: Lan
authors.initials: L
authors.lastname: Shen
authors.forename: Fuyang
authors.initials: F
authors.lastname: Li
authors.forename: Jicun
authors.initials: J
authors.lastname: Wang
authors.forename: Jiong
authors.initials: J
authors.lastname: Han
authors.forename: Libo
authors.initials: L
authors.lastname: Yao
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry*; D019556:COS Cells; D002460:Cell Line; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004285:Dogs; D004837:Epinephrine / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D006801:Humans; D019169:Jurkat Cells; D010455:Peptides / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry*; D011485:Protein Binding / Q000235:genetics; D011493:Protein Kinase C / Q000235:genetics* / Q000378:metabolism; D064546:Protein Kinase C beta; D017434:Protein Structure, Tertiary / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000378:metabolism*; D020298:U937 Cells; D051552:beta-Adrenergic Receptor Kinases
chemical_list: D001798:Blood Proteins; D010455:Peptides; D010750:Phosphoproteins; D012097:Repressor Proteins; D015534:Trans-Activators; C039077:platelet protein P47; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D051552:beta-Adrenergic Receptor Kinases; D004837:Epinephrine