Voltage-dependent Ca2+ channel subunit expression and immunolocalization in mouse spermatogenic cells and sperm

Though voltage-dependent Ca2+ channels contribute to the orchestratation of sperm differentiation and function, many questions remain concerning their molecular architecture. This study shows that alpha(1A) and alpha(1C) Ca2 channel pore-forming subunits are expressed in spermatogenic cells. In add ition, it provides what is to our knowledge the first evidence for the pres ence of the Ca2+ channel beta auxiliary subunits in spermatogenic cells and sperm. Using RT-PCR we demonstrated the expression of all four known genes encoding the beta subunits in spermatogenic cells. Specific antibodies det ected three of these proteins in spermatogenic cells and sperm. In spermato genic cells both alpha(1) and beta subunits are diffusely distributed throu ghout the cytoplasm,while in sperm they appear to be regionally localized. (C) 1999 Federation of European Biochemical Societies.