GTPase activity protein preparation

Pertussis toxin-resistant G-proteins are known to lack the cysteine residue in the C terminus and this is also characteristic for the G-proteins of the Gaq family (Exton, 1994). Antisera prepared against the C-termi-nal peptide sequences, common to Gaq and Gan, were found to block GTPase and PI-PLC activity, in cell membrane preparations, stimulated by specific ligands such as tromboxane A2, bradykinin, angiotensin II, vasopressin, and histamine. The data indicate that the Gaq proteins are responsible for regulation of PI-PLC by G-protein-linked receptors (Rhee and Choi, 1992a Sternweis and Smrcka, 1992). 

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