Binding of PH domains of beta-adrenergic receptor kinase and beta-spectrin to WD40/beta-transducin repeat containing regions of the beta-subunit of trimeric G-proteins.
Pleckstrin homology (PH) domains are found in numerous proteins important in signal transduction and cytoskeletal function. Several PH domains are now known to contain a binding site for the beta gamma subunits of trimeric G-proteins (G beta gamma), a finding which naturally raises the question of where on the G beta gamma complex these PH domains bind. Here we demonstrate binding of the PH domains of beta-adrenergic receptor kinase and beta-spectrin to the G beta subunit and not the G gamma subunit in a nitrocellulose gel replica assay. Furthermore, the C-terminal tryptic fragment of G beta containing only 5 WD40/beta-transducin (WD40) repeats also binds these two PH domains. Finally, constructs containing only WD40 repeats of G beta were shown to bind to beta-ARK and beta-spectrin PH domains in solution. These findings suggest that WD40 repeats of G beta are ligands for PH domains and have interesting implications for other proteins containing WD40 sequences.
Wang
D S
DS
University of Florida, Department of Neuroscience, Gainesville 32610.
Shaw
R
R
Winkelmann
J C
JC
Shaw
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D002417:Cattle; D002848:Chromatography, DEAE-Cellulose; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry* / Q000378:metabolism*; D005260:Female; D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000302:isolation & purification; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013049:Spectrin / Q000737:chemistry* / Q000378:metabolism*; D015293:Transducin / Q000378:metabolism*; D051552:beta-Adrenergic Receptor Kinases
D046911:Macromolecular Substances; D011993:Recombinant Fusion Proteins; D013049:Spectrin; D017868:Cyclic AMP-Dependent Protein Kinases; D051552:beta-Adrenergic Receptor Kinases; D019204:GTP-Binding Proteins; D015293:Transducin