Pertussis toxin exerts it
Pertussis toxin exerts its effects by ribosylating a specific residue on one of these, which prevents it from being activated. Cholera toxin works in a similar manner, but it causes these to be constitutively active. The prominent oncogene Ras codes for one of these, and the beta-adrenergic receptor kinase prevents them from associating with their receptors, which have seven transmembrane domains. When activated by their receptors, the beta and gamma subunits remain attached, but the alpha subunit often sets off a second messenger cascade by activating enzymes like phospholipase C. FTP name these ubiquitous proteins found on the inner surfaces of cell membranes, named for their binding of the nucleotides GDP and GTP.
Pertussis toxin exerts its effects by ribosylating a specific residue on one of these, which prevents it from being activated.
G Proteins