First Author | Nishimura H | Year | 2007 |
Journal | J Biol Chem | Volume | 282 |
Issue | 24 | Pages | 17900-7 |
PubMed ID | 17439939 | Mgi Jnum | J:123000 |
Mgi Id | MGI:3716230 | Doi | 10.1074/jbc.M702268200 |
Citation | Nishimura H, et al. (2007) Identification of an ADAM2-ADAM3 complex on the surface of mouse testicular germ cells and cauda epididymal sperm. J Biol Chem 282(24):17900-7 |
abstractText | Male mice lacking ADAM2 (fertilin beta) or ADAM3 (cyritestin) are infertile; cauda epididymal sperm (mature sperm) from these mutant mice cannot bind to the egg zona pellucida. ADAM3 is barely present in Adam2-null sperm, despite normal levels of this protein in Adam2-null testicular germ cells (TGCs; sperm precursor cells). Here, we have explored the molecular basis for the loss of ADAM3 in Adam2-null TGCs to clarify the biosynthetic and functional linkage of ADAM2 and ADAM3. A small portion of total ADAM3 was found present on the surface of wild-type and Adam2(-/-) TGCs at similar levels. In the Adam2-null TGCs, however, surface-localized ADAM3 exhibited an increased amount of an endoglycosidase H-resistant form that may be related to instability of ADAM3. Moreover, we found a complex between ADAM2 and ADAM3 on the surface of TGCs and sperm. The intracellular chaperone calnexin was a component of the testicular ADAM2-ADAM3 complex. Our findings suggest that the association with ADAM2 is a key element for stability of ADAM3 in epididymal sperm. The presence of the ADAM2-ADAM3 complex in sperm also suggests a potential role of ADAM2 with ADAM3 in sperm binding to the egg zona pellucida. |