A surface of the kinase domain critical for the allosteric activation of G protein-coupled receptor kinases. Export

@article{citeulike:4469795, abstract = {G protein-coupled receptor (GPCR) kinases (GRKs) phosphorylate activated GPCRs and initiate their desensitization. Many prior studies suggest that activated GPCRs dock to an allosteric site on the GRKs and thereby stimulate kinase activity. The extreme N-terminal region of GRKs is clearly involved in this process, but its role is not understood. Using our recent structure of bovine GRK1 as a guide, we generated mutants of solvent-exposed residues in the GRK1 kinase domain that are conserved among GRKs but not in the extended protein kinase A, G and C (AGC) family and evaluated their catalytic activity. Mutation of select residues in strands beta1 and beta3 of the kinase small lobe, alphaD of the kinase large lobe, and the AGC kinase C-tail greatly impaired receptor phosphorylation. The most dramatic effect was observed for mutation of an invariant arginine on the beta1 strand (\~{}1000-fold decrease in k(cat)/K(M)). These residues form a continuous surface that is uniquely available in GRKs for protein-protein interactions. Surprisingly, these mutants, as well as a 19-amino acid N-terminal truncation of GRK1, also show decreased catalytic efficiency for peptide substrates, although to a lesser extent than for receptor phosphorylation. Our data suggest that the N-terminal region and the newly identified surface interact and stabilize the closed, active conformation of the kinase domain. Receptor binding is proposed to promote this interaction, thereby enhancing GRK activity.}, author = {Huang, Chih-Chin C. and Yoshino-Koh, Kae and Tesmer, John J G J.}, citeulike-article-id = {4469795}, citeulike-linkout-0 = {http://dx.doi.org/10.1074/jbc.M809544200}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19364770}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19364770}, day = {13}, doi = {10.1074/jbc.M809544200}, issn = {0021-9258}, journal = {The Journal of biological chemistry}, keywords = {gpcr, grk, kinase, protein\_docking}, month = {April}, posted-at = {2009-05-06 10:02:59}, priority = {2}, title = {A surface of the kinase domain critical for the allosteric activation of G protein-coupled receptor kinases.}, url = {http://dx.doi.org/10.1074/jbc.M809544200}, year = {2009} }

TY - JOUR ID - citeulike:4469795 L3 - citeulike-article-id:4469795 N2 - G protein-coupled receptor (GPCR) kinases (GRKs) phosphorylate activated GPCRs and initiate their desensitization. Many prior studies suggest that activated GPCRs dock to an allosteric site on the GRKs and thereby stimulate kinase activity. The extreme N-terminal region of GRKs is clearly involved in this process, but its role is not understood. Using our recent structure of bovine GRK1 as a guide, we generated mutants of solvent-exposed residues in the GRK1 kinase domain that are conserved among GRKs but not in the extended protein kinase A, G and C (AGC) family and evaluated their catalytic activity. Mutation of select residues in strands beta1 and beta3 of the kinase small lobe, alphaD of the kinase large lobe, and the AGC kinase C-tail greatly impaired receptor phosphorylation. The most dramatic effect was observed for mutation of an invariant arginine on the beta1 strand (~1000-fold decrease in k(cat)/K(M)). These residues form a continuous surface that is uniquely available in GRKs for protein-protein interactions. Surprisingly, these mutants, as well as a 19-amino acid N-terminal truncation of GRK1, also show decreased catalytic efficiency for peptide substrates, although to a lesser extent than for receptor phosphorylation. Our data suggest that the N-terminal region and the newly identified surface interact and stabilize the closed, active conformation of the kinase domain. Receptor binding is proposed to promote this interaction, thereby enhancing GRK activity. JF - The Journal of biological chemistry SN - 0021-9258 TI - A surface of the kinase domain critical for the allosteric activation of G protein-coupled receptor kinases. KW - gpcr KW - grk KW - kinase KW - protein_docking AU - Huang, Chih-Chin AU - Yoshino-Koh, Kae AU - Tesmer, John J G PY - 2009/04/13/ UR - http://dx.doi.org/10.1074/jbc.M809544200 ER -