Stimulation of phospholipase C by a mutationally activated G protein alpha 16 subunit.
Alpha 16, a member of the alpha q subfamily of G protein alpha subunits, was recently identified in human hematopoietic cells. In order to elucidate the function of this novel alpha subunit, we cloned and mutagenized its cDNA to obtain a constitutively active protein. COS-1 cells were transfected with both wild-type and mutant cDNAs. Expression was confirmed by immunoblotting using a rabbit antiserum raised against the C-terminal decapeptide of alpha 16. The constitutively activated mutant alpha 16-R186C caused a two-fold increase in the formation of inositol trisphosphate in intact COS-1 cells, while the wild-type alpha 16 subunit had no effect. We conclude that alpha 16 is involved in coupling cell surface receptors of human hematopoietic cells to stimulation of phospholipase C.
Schnabel
P
P
Molecular Pharmacology, Division, German Cancer Research Center, Heidelberg, FRG.
Schreck
R
R
Schiller
D L
DL
Camps
M
M
Gierschik
P
P
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007295:Inositol Phosphates / Q000032:analysis; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D010738:Type C Phospholipases / Q000187:drug effects*
D007295:Inositol Phosphates; D011994:Recombinant Proteins; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins