Inhibits signal transduction by increasing the GTPase activity of G protein alpha subunits thereby driving them into their inactive GDP-bound form. Interacts with GNA11, GNA12 AND GNA13. Expressed in the cytoplasm of spermatogonia and spermatocytes. In spermatids, also expressed in the nucleus. Expressed testis, including in Leydig cells and spermatogenic cells from the spermatogonia to spermatid stages (at protein level).