Testis Expressed Protein 101 (TEX101)

The deduced 249-amino acid protein shares 55% amino acid identity with its mouse homolog. TEX101 is a member of the urokinase receptor family and shares 32% identity with PRV1. Northern blot analysis of 61 human tissues detected a 1.55-kb transcript in testis with trace expression in liver and peripheral blood lymphocytes.

Immunohistochemical studies of mouse tissues detected Tex101 protein on the cell surfaces of some prospermatogonia and after initiation of spermatogenesis. By day 12 to 28 days postpartum, Tex101 was detected on the plasma membranes of spermatocytes and spermatids, but not on spermatogonia. Tex101 was also detected on embryonic female germ cells, but expression declined after 6 days postpartum.