CHARACTERIZATION AND LOCALIZATION OF THE RAT, MOUSE AND HUMAN TESTICULAR PHOSPHATIDYLETHANOLAMINE BINDING-PROTEIN

A cytosolic 23kDa protein was initially purified from bovine brain and shown to bind phosphatidylethanolamine. Later, it was also characteri zed in rat and human brain, and it is now known to be widespread, havi ng been found in numerous tissues in several species. Here, we report the high level of mRNA and phosphatidyl ethanolamine binding protein e xpression in rat testis and to a lesser extent in mouse testis. In hum an testis, although it was not detectable by Northern blot analysis, t he mRNA was shown to be present when PCR amplification was performed. Immunohistochemical experiments revealed that the testicular phosphati dylethanolamine binding protein (tPBP) is principally expressed in the elongated spermatids of both rat and mouse testis. This finding, and the association of tPBP with cellular membranes, suggest its possible implication in membrane remodelling during spermatid maturation.