Identification of rab12 as a vesicle-associated small GTPase highly expressed in Sertoli cells of rat testis

• Published in: Molecular reproduction and development Vol. 71; no. 2; pp. 178 - 185
• Main Authors: Iida, Hiroshi, Noda, Mariko, Kaneko, Takane, Doiguchi, Masamichi, Mōri, Takayuki
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.06.2005; Wiley-Liss
• Subjects: a small GTPase; Animals; Biological and medical sciences; Cytoplasmic Vesicles - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - physiology; Male; Mammalian male genital system; Morphology. Physiology; rab GTP-Binding Proteins - biosynthesis; rab12; Rats; Rats, Wistar; Sertoli cell; Sertoli Cells - cytology; Sertoli Cells - metabolism; testis; Vertebrates: reproduction; rab12; Sertoli cell; Rat; Enzyme; Triphosphoric monoester hydrolases; Rodentia; dGTPase; Esterases; testis; Testicle; Gene expression; Male genital system; In vitro; Kidney; Vertebrata; Mammalia; Cell line; a small GTPase; Hydrolases; Localization
• ISSN: 1040-452X; 1098-2795
• DOI: 10.1002/mrd.20294

We examined the expression and the localization of a small GTPase, rab12, in rat testis. Northern blot analysis showed that 2.3 kb transcript of rab12 was expressed in rat testis. RT‐PCR analysis indicated constant expression of rab12 throughout testis development. Immunohistochemical studies revealed that rab12 protein was highly expressed in Sertoli cells in the seminiferous tubules, while both spermatogenic germ cells and interstitial cells exhibited faint or no immunosignal for rab12. The expression pattern of rab12 in Sertoli cells varied between the tubules: its immunostaining appeared as a wheel‐like pattern at stage I ∼ III and as a luminal staining pattern at stage IV ∼ VI, whereas the immunostaining signals were only rudimentary detected at stage VIII and thereafter (∼stage XIV). The diversified staining pattern of rab12 in the tubules seemed to reflect either the different shape of Sertoli cells during the cycle of the seminiferous epithelium or the variant expression levels of rab12 in Sertoli cells at each stage of the tubules. In cultured rat Sertoli cells and normal rat kidney (NRK) cells, rab12 was found to be associated with small vesicles distributed throughout the cytoplasm, but not with the Golgi apparatus. When overexpressed in NRK cells, rab12‐associated small vesicles were not only distributed throughout the cytoplasm but also accumulated in the perinuclear cytoplasm around centrosome. We interrupt these data as a potential role of rab12 in acceleration of vesicular transport from the cell periphery to the perinuclear centrosome region. Mol. Reprod. Dev. 71: 178–185, 2005. © 2005 Wiley‐Liss, Inc.