An intact N terminus of the γ subunit is required for the Gβγ stimulation of rhodopsin phosphorylation by human β-adrenergic receptor kinase-1 but not for kinase binding

Taraneh N. Haske, Antonio DeBlasi, Harry LeVine

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

Cleavage after lysine 32 in the Gγ2 subtype and after lysine 36 in the Gγ3 subtype of purified mixed brain Gβγ by endoproteinase Lys-C blocks Gβγ-mediated stimulation of phosphorylation of rhodopsin in urea-extracted rod outer segments by recombinant human β-adrenergic receptor kinase (hβARK1) holoenzyme while hβARK1 binding to rod outer segments is partially affected. This treatment does not attenuate the binding of the treated Gβγ to C-terminal fragments of hβARK1 containing the pleckstrin homology domain. Lys-C proteolysis also does not alter the association of the Gβγ with phospholipids, its ability to support pertussis toxin-catalyzed Gα(o)/Gα(i) ADP-ribosylation, or its ability to inhibit forskolin-stimulated platelet adenylate cyclase. The Gβ subunit remains noncovalently associated with the cleaved Gγ fragments. Thus, in addition to recruiting hβARK1 to its receptor substrate, Gγ contributes secondary and/or tertiary structural features to activate the kinase.

Original languageEnglish
Pages (from-to)2941-2948
Number of pages8
JournalJournal of Biological Chemistry
Volume271
Issue number6
DOIs
StatePublished - Feb 9 1996

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint

Dive into the research topics of 'An intact N terminus of the γ subunit is required for the Gβγ stimulation of rhodopsin phosphorylation by human β-adrenergic receptor kinase-1 but not for kinase binding'. Together they form a unique fingerprint.

Cite this