DIRAS Family, GTP Binding RAS Like 2 (DIRAS2)

DIRAS2 belongs to a distinct branch of the functionally diverse Ras superfamily of monomeric GTPases.The deduced 199-amino acid protein contains conserved phosphate/Mg(2+)-binding regions, an effector domain, conserved guanine base-interacting residues, and a C-terminal prenylation motif.

DIRAS2 shares 79% identity with DIRAS1 and 32 to 40% identity with other Ras family members. Northern blot analysis revealed strong expression of a 4.4-kb transcript in whole brain and in most brain regions examined. Expression was weak or undetectable in all other tissues tested.As predicted by these changes, DIRAS1 and DIRAS2 displayed low GTPase activity and existed predominantly in the GTP-bound form in transfected cells.