Could be a regulatory protein, possibly participating in receptor-mediated signal transduction at the plasma membrane. Has guanine nucleotide-binding activity but undetectable intrinsic GTPase activity (By similarity). Interacts with calmodulin in a Ca(2+)-dependent manner. Binds ROCK1 (By similarity). Phosphorylated on tyrosine residues. Belongs to the small GTPase superfamily. RGK family.