title: Differential localization of ADAM1a and ADAM1b in the endoplasmic reticulum of testicular germ cells and on the surface of epididymal sperm.
abstract: Although fertilin is a heterodimeric complex between ADAM1 (A Disintegrin And Metalloprotease 1, fertilin alpha) and ADAM2 (fertilin beta) located on the sperm surface, two different ADAM1 isoforms, ADAM1a and ADAM1b, are present in the mouse testis. In this study, we have examined the localization of ADAM1a and ADAM1b in testicular germ cells and epididymal sperm. ADAM1a was restrictedly present within the endoplasmic reticulum of germ cells, whereas epididymal sperm contained only ADAM1b on the cell surface. The precursors of ADAM1a and ADAM1b formed a heterodimeric complex with that of ADAM2 in the endoplasmic reticulum of germ cells. The heterodimeric complex between the mature forms of ADAM1b and ADAM2 was also found on the sperm surface. These data imply the potential roles of ADAM1a and ADAM1b in spermatogenesis and fertilization, respectively.
authors.affiliation: Institute of Applied Biochemistry, University of Tsukuba, 1-1-1 Tennodai, Tsukuba Science City, Ibaraki-ken, 305-8572, Japan.
authors.forename: Ekyune
authors.initials: E
authors.lastname: Kim
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nishimura
authors.forename: Tadashi
authors.initials: T
authors.lastname: Baba
mesh_terms: D051722:ADAM Proteins; D000818:Animals; D002460:Cell Line; D019281:Dimerization; D004721:Endoplasmic Reticulum / Q000737:chemistry*; D004822:Epididymis / Q000166:cytology; D000072196:Fertilins; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism; D008666:Metalloendopeptidases / Q000032:analysis* / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D011498:Protein Precursors / Q000378:metabolism; D013094:Spermatozoa / Q000737:chemistry*; D013737:Testis / Q000166:cytology*
chemical_list: D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011498:Protein Precursors; D051722:ADAM Proteins; C000606454:ADAM2 protein, human; C000606455:Adam1a protein, mouse; C000606457:Adam1b protein, mouse; C000606458:Adam2 protein, mouse; D000072196:Fertilins; D008666:Metalloendopeptidases