title: Intratesticular localization of the organic solute carrier protein, OSCP1, in spermatogenic cells in mice.
abstract: Organic solute carrier protein 1 (OSCP1) is a recently described human gene that facilitates the transport of various organic solutes into the cell, when expressed in frog eggs. In this study, we cloned a mouse ortholog of OSCP1 encoding 379 amino acid protein, with 94% homology to the human counterpart. The mouse OSCP1 mRNA was predominantly expressed in the testis, in which it was attributed to the spermatogenic cells, except the spermatogonia. Immunohistochemistry confirmed that OSCP1 protein is continuously expressed during spermatogenesis in a stage- and cell type-specific manner, in the leptotene spermatocytes at stage IX through step 15 spermatids. Subcellular fractionation of mouse testis homogenates indicated that OSCP1 is a 45-kDa cytosolic protein. Moreover, when green fluorescent protein-OSCP1 fusion constructs were transfected into cultured cells, the fluorescence localized evenly in the cytoplasm. These results suggest that mouse testis OSCP1 may indirectly mediate substrate uptake into meiotic and spermiogenic germ cells, within the cytosol.
authors.affiliation: Toxicology Laboratory, Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., Kanagawa, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Hiratsuka
authors.forename: Shan-Ai
authors.initials: SA
authors.lastname: Yin
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ohtomo
authors.forename: Mariko
authors.initials: M
authors.lastname: Fujita
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Ohtsuki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Isaka
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Suga
authors.forename: Tohru
authors.initials: T
authors.lastname: Kurosawa
authors.forename: Junji
authors.initials: J
authors.lastname: Yamada
mesh_terms: D000818:Animals; D003600:Cytosol / Q000378:metabolism; D008297:Male; D026901:Membrane Transport Proteins / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D013091:Spermatogenesis; D013093:Spermatogonia / Q000378:metabolism*; D013737:Testis / Q000378:metabolism*
chemical_list: D026901:Membrane Transport Proteins; C521274:Oscp1 protein, mouse