This chapter discusses purification of recombinant Gqα, G11α, and G16α from Sf9 cells. The Gqα subfamily consists of five members: Gqα, G11α, G14α, G15α, and G16α. The G15α and G16α are similar to one another (85% identity) and may represent the mouse and human homologs of the same gene. All members of the Gq class lack the cysteine residue near the carboxyl terminus that is covalently modified (ADP-ribosylated) by pertussis toxin in members of the Gi class of α subunits. Thus, Gq family members are thought to couple cell surface receptors to signaling pathways that are insensitive to this toxin. A wide variety of hormones, neurotransmitters, and growth factors activate phospholipase C (PLC) which, in turn, generates two second messengers, inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] and diacylglycerol. Members of the Gq subfamily have been shown to link cell surface receptors to stimulation of the three known β isoforms of PLC.
ASJC Scopus subject areas
- Molecular Biology