A subset of growth hormone-secreting human pituitary tumours carries somatic mutations that inhibit GTPase activity of a G protein α chain, αs. The resulting activation of adenylyl cyclase bypasses the cells' normal requirement for trophic hormone. Amino acids substituted in the putative gsp oncogene identify a domain of G protein α-chains required for intrinsic ability to hydrolyse GTP. This domain may serve as a built-in counter-part of the separate GTPase-activating proteins required for GTP hydrolysis by small GTP-binding proteins such as p21ras.
|Number of pages||5|
|Publication status||Published - 1989|
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