Overexpression of beta-arrestin and beta-adrenergic receptor kinase augment desensitization of beta 2-adrenergic receptors.

Published

Journal Article

Receptor-specific or homologous desensitization of beta 2-adrenergic receptors is thought to be effected via phosphorylation of the receptor by the beta-adrenergic receptor kinase (beta ARK), followed by binding of beta-arrestin. We have generated stably transfected Chinese hamster ovary cell lines overexpressing either of the two regulatory proteins and also expressing low or high levels of beta 2-adrenergic receptors (approximately 80 and approximately 600 fmol/mg of membrane protein). In these cells, we studied the process of desensitization induced by the beta-adrenergic receptor agonist isoproterenol. In cells expressing high levels of beta 2-adrenergic receptors, desensitization to high concentrations of isoproterenol (previously shown to be mediated by both beta ARK and protein kinase A) amounted to approximately 50% in control cells, approximately 80% in beta ARK-overexpressing cells, and approximately 90% in beta-arrestin-overexpressing cells. In cells expressing low levels of beta 2-adrenergic receptors, these values were approximately 50, approximately 60, and approximately 60%, respectively. Desensitization to low concentrations of isoproterenol (previously shown to be essentially protein kinase A-mediated and not receptor-specific, i.e. heterologous) was not affected by overexpression of either beta ARK or beta-arrestin. These data suggest that in cells expressing high levels of beta 2-adrenergic receptors, beta-arrestin and beta ARK become limiting for homologous receptor desensitization. They provide further support for the involvement of these two proteins in the regulation of beta 2-adrenergic receptor function.

Full Text

Duke Authors

Cited Authors

  • Pippig, S; Andexinger, S; Daniel, K; Puzicha, M; Caron, MG; Lefkowitz, RJ; Lohse, MJ

Published Date

  • February 1993

Published In

Volume / Issue

  • 268 / 5

Start / End Page

  • 3201 - 3208

PubMed ID

  • 8381421

Pubmed Central ID

  • 8381421

Electronic International Standard Serial Number (EISSN)

  • 1083-351X

International Standard Serial Number (ISSN)

  • 0021-9258

Language

  • eng