%0 Journal Article %1 Roth1991 %A Roth, N. S. %A Campbell, P. T. %A Caron, M. G. %A Lefkowitz, R. J. %A Lohse, M. J. %D 1991 %J Proc Natl Acad Sci U S A %K *Cyclic A/pharmacology AMP-Dependent Carcinoma, Cell Concanavalin GTP-Binding Humans Isoproterenol/*pharmacology Kinases Kinases/*metabolism Kinetics Line Membrane Permeability Protein Proteins/metabolism Receptor Squamous beta-Adrenergic beta/drug effects/*metabolism Adrenergic %N 14 %P 6201-4 %T Comparative rates of desensitization of beta-adrenergic receptors by the beta-adrenergic receptor kinase and the cyclic AMP-dependent protein kinase %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1648731 %V 88 %X Three separate processes may contribute to rapid beta-adrenergic receptor desensitization: functional uncoupling from the stimulatory guanine nucleotide-binding protein Gs, mediated by phosphorylation of the receptors by two distinct kinases, the specific beta-adrenergic receptor kinase (beta ARK) and the cyclic AMP-dependent protein kinase A (PKA), as well as a spatial uncoupling via sequestration of the receptors away from the cell surface. To evaluate the relative importance and potential role of the various processes in different physiological situations, a kinetic analysis of these three mechanisms was performed in permeabilized A431 epidermoid carcinoma cells. To allow a separate analysis of each mechanism, inhibitors of the various desensitization mechanisms were used: heparin to inhibit beta ARK, the PKA inhibitor peptide PKI to inhibit PKA, and concanavalin A treatment to prevent sequestration. Isoproterenol-induced phosphorylation of beta 2 receptors in these cells by beta ARK occurred with a t1/2 of less than 20 sec, whereas phosphorylation by PKA had a t1/2 of about 2 min. Similarly, beta ARK-mediated desensitization of the receptors proceeded with a t1/2 of less than 15 sec, and PKA-mediated desensitization with a t1/2 of about 3.5 min. Maximal desensitization mediated by the two kinases corresponded to a reduction of the signal-transduction capacity of the receptor/adenylyl cyclase system by about 60% in the case of beta ARK and by about 40% in the case of PKA. Receptor sequestration was much slower (t1/2 of about 10 min) and involved no more than 30% of the cell surface receptors. It is concluded that beta ARK-mediated phosphorylation is the most rapid and quantitatively most important factor contributing to the rapid desensitization. This rapidity of the beta ARK-mediated mechanism makes it particularly well suited to regulate beta-adrenergic receptor function in rapidly changing environments such as the synaptic cleft.

@article{Roth1991, abstract = {Three separate processes may contribute to rapid beta-adrenergic receptor desensitization: functional uncoupling from the stimulatory guanine nucleotide-binding protein Gs, mediated by phosphorylation of the receptors by two distinct kinases, the specific beta-adrenergic receptor kinase (beta ARK) and the cyclic AMP-dependent protein kinase A (PKA), as well as a spatial uncoupling via sequestration of the receptors away from the cell surface. To evaluate the relative importance and potential role of the various processes in different physiological situations, a kinetic analysis of these three mechanisms was performed in permeabilized A431 epidermoid carcinoma cells. To allow a separate analysis of each mechanism, inhibitors of the various desensitization mechanisms were used: heparin to inhibit beta ARK, the PKA inhibitor peptide PKI to inhibit PKA, and concanavalin A treatment to prevent sequestration. Isoproterenol-induced phosphorylation of beta 2 receptors in these cells by beta ARK occurred with a t1/2 of less than 20 sec, whereas phosphorylation by PKA had a t1/2 of about 2 min. Similarly, beta ARK-mediated desensitization of the receptors proceeded with a t1/2 of less than 15 sec, and PKA-mediated desensitization with a t1/2 of about 3.5 min. Maximal desensitization mediated by the two kinases corresponded to a reduction of the signal-transduction capacity of the receptor/adenylyl cyclase system by about 60% in the case of beta ARK and by about 40% in the case of PKA. Receptor sequestration was much slower (t1/2 of about 10 min) and involved no more than 30% of the cell surface receptors. It is concluded that beta ARK-mediated phosphorylation is the most rapid and quantitatively most important factor contributing to the rapid desensitization. This rapidity of the beta ARK-mediated mechanism makes it particularly well suited to regulate beta-adrenergic receptor function in rapidly changing environments such as the synaptic cleft.}, added-at = {2010-12-14T18:12:02.000+0100}, author = {Roth, N. S. and Campbell, P. T. and Caron, M. G. and Lefkowitz, R. J. and Lohse, M. J.}, biburl = {https://www.bibsonomy.org/bibtex/2e3dd4af97f8fcdb96042b2c5339e70f0/pharmawuerz}, endnotereftype = {Journal Article}, interhash = {0dc9b238e41c309c8f696eccfc579658}, intrahash = {e3dd4af97f8fcdb96042b2c5339e70f0}, issn = {0027-8424 (Print) 0027-8424 (Linking)}, journal = {Proc Natl Acad Sci U S A}, keywords = {*Cyclic A/pharmacology AMP-Dependent Carcinoma, Cell Concanavalin GTP-Binding Humans Isoproterenol/*pharmacology Kinases Kinases/*metabolism Kinetics Line Membrane Permeability Protein Proteins/metabolism Receptor Squamous beta-Adrenergic beta/drug effects/*metabolism Adrenergic}, month = {Jul 15}, note = {Roth, N S Campbell, P T Caron, M G Lefkowitz, R J Lohse, M J HL16037/HL/NHLBI NIH HHS/United States Comparative Study Research Support, U.S. Gov't, P.H.S. United states Proceedings of the National Academy of Sciences of the United States of America Proc Natl Acad Sci U S A. 1991 Jul 15;88(14):6201-4.}, number = 14, pages = {6201-4}, shorttitle = {Comparative rates of desensitization of beta-adrenergic receptors by the beta-adrenergic receptor kinase and the cyclic AMP-dependent protein kinase}, timestamp = {2010-12-14T18:22:42.000+0100}, title = {Comparative rates of desensitization of beta-adrenergic receptors by the beta-adrenergic receptor kinase and the cyclic AMP-dependent protein kinase}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1648731}, volume = 88, year = 1991 }