Hiratsuka Kazuyuki, Yin Shan-Ai, Ohtomo Takayuki, Fujita Mariko, Ohtsuki Kazutoshi, Isaka Hiroyuki, Suga Tetsuya, Kurosawa Tohru, Yamada Junji
Toxicology Laboratory, Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., Kanagawa, Japan.
Mol Reprod Dev. 2008 Oct;75(10):1495-504. doi: 10.1002/mrd.20893.
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.
有机溶质载体蛋白1（OSCP1）是最近描述的一种人类基因，当在蛙卵中表达时，它有助于各种有机溶质转运进入细胞。在本研究中，我们克隆了OSCP1的小鼠直系同源基因，其编码379个氨基酸的蛋白质，与人类对应物具有94%的同源性。小鼠OSCP1 mRNA主要在睾丸中表达，在睾丸中它存在于生精细胞中，但不包括精原细胞。免疫组织化学证实，OSCP1蛋白在精子发生过程中以阶段和细胞类型特异性的方式持续表达，从第IX期的细线期精母细胞到第15步的精子细胞。小鼠睾丸匀浆的亚细胞分级分离表明，OSCP1是一种45 kDa的胞质蛋白。此外，当绿色荧光蛋白-OSCP1融合构建体转染到培养细胞中时，荧光均匀地定位于细胞质中。这些结果表明，小鼠睾丸OSCP1可能在胞质溶胶中间接介导底物摄取到减数分裂和精子发生的生殖细胞中。
