| First Author | Berruti G | Year | 2001 |
| Journal | Biol Reprod | Volume | 65 |
| Issue | 2 | Pages | 488-95 |
| PubMed ID | 11466217 | Mgi Jnum | J:193087 |
| Mgi Id | MGI:5467543 | Doi | 10.1095/biolreprod65.2.488 |
| Citation | Berruti G, et al. (2001) MSJ-1, a mouse testis-specific DnaJ protein, is highly expressed in haploid male germ cells and interacts with the testis-specific heat shock protein Hsp70-2. Biol Reprod 65(2):488-95 |
| abstractText | The MSJ-1 gene encodes a murine DnaJ homologue that is expressed specifically in adult testis. DnaJ proteins act as cochaperones of Hsp70 proteins in promoting diverse cellular functions. In this study we used recombinant MSJ-1 proteins to produce MSJ-1 antiserum and to carry out in vitro binding assays. In a wide immunoscreening of mouse tissues, affinity-purified MSJ-1 antibodies recognize a unique protein of 30 kDa in male germ cells only. MSJ-1 is able to interact with the testis-specific Hsp70-2 protein and can be coimmunoprecipitated with Hsp70-2 from spermatogenic cells; binding of these two chaperones is consistent with the presence of a third component, which is so far unknown. MSJ-1 is weakly detected in early round spermatids, and its protein content increases in cytodifferentiating spermatids where it colocalizes with the developing acrosome and their postnuclear region. Hsp70-2, which is known to be highly expressed in meiotic cells, shows a subcellular localization in late differentiating spermatids that overlaps that of MSJ-1. MSJ-1 is also maintained in testicular and epididymal spermatozoa, where it sharply demarcates into two distinct cell areas; the outer surface of the acrosomal vesicle, and the centrosomal area. On the whole, our findings are consistent with a role for MSJ-1 in acrosome formation and centrosome adjustment during spermatid development, whereas its presence in mature spermatozoa suggests a special function during fertilization, shortly afterward, or both. |
