When activated, the alpha subunit separates and activates adenylyl cyclase, causing production of the second messenger cyclic AMP.
Cholera toxin irreversibly adds an ADP-ribosyl group to the alpha subunit of these, essentially causing permanent activation. The proteins that couple to them contain seven membrane spanning helical regions, with loops between the helices that extend into the cytosol and interact with them. Examples of such coupled receptors include rhodopsins and beta-adrenergic receptors. When activated, the alpha subunit separates and activates adenylyl cyclase, causing production of the second messenger cyclic AMP. FTP, what are these trimeric proteins important in signal transduction, named for their use of GDP and GTP as molecular regulators?
Cholera toxin irreversibly adds an ADP-ribosyl group to the alpha subunit of these, essentially causing permanent activation.
G proteins or guanine nucleotide binding protein