Dictyostelium discoideum
Essential in "Dictyostelium discoideum". This is evidenced by severe developmental failure in deficient "ras" expression and by significant impairment of various life activities when artificially expressed, such as: increased concentration of inositol phosphates; likely reduction of cAMP binding to chemotaxis receptors; and that is likely the reason cGMP synthesis is impaired. Adenylate cyclase activity is unaffected by "ras".