Substitution of an extracellular cysteine in the beta 2-adrenergic receptor enhances agonist-promoted phosphorylation and receptor desensitization.

Published

Journal Article

We constructed and expressed in a permanent cell line a beta 2-adrenergic receptor with a valine substitution for cysteine 184 of the second putative extracellular loop. The mutant receptor was partially uncoupled from adenylyl cyclase with impaired ability to form the high affinity agonist-receptor-G protein complex, yet displayed more rapid and extensive agonist-induced desensitization. The enhanced desensitization was accompanied by increased agonist promoted, but not cAMP promoted, receptor phosphorylation in intact cells. Thus, not only is impaired desensitization associated with decreased phosphorylation, as we have shown with several mutant beta 2-adrenergic receptors recently, but enhanced desensitization is accompanied by increased agonist promoted receptor phosphorylation. In the case of this cysteine mutant, this may be due to the greater accessibility of the uncoupled receptor for phosphorylation by the beta-adrenergic receptor kinase.

Full Text

Duke Authors

Cited Authors

  • Liggett, SB; Bouvier, M; O'Dowd, BF; Caron, MG; Lefkowitz, RJ; DeBlasi, A

Published Date

  • November 1989

Published In

Volume / Issue

  • 165 / 1

Start / End Page

  • 257 - 263

PubMed ID

  • 2556136

Pubmed Central ID

  • 2556136

Electronic International Standard Serial Number (EISSN)

  • 1090-2104

International Standard Serial Number (ISSN)

  • 0006-291X

Digital Object Identifier (DOI)

  • 10.1016/0006-291x(89)91063-2

Language

  • eng