title: Co-localization of a novel transcriptional repressor simiRP58 with RP58.
abstract: We have cloned a novel transcriptional repressor protein, termed simiRP58, which has high homology to RP58. Both simiRP58 and RP58 belong to the POZ domain and Kruppel Zn finger (POK) family of proteins. Using the luciferase assay system, we found that simiRP58 also has transcriptional repressor activity like RP58. Northern blotting and quantitative RT-PCR showed that simiRP58 was expressed in testes at the highest level. In situ hybridization of testes showed that simiRP58 is expressed by spermatocytes in only a portion of the seminiferous tubules. In contrast, expression of RP58 by spermatocytes was ubiquitous in all seminiferous tubules. Using COS-7 cells, we observed that simiRP58 was localized in the cytoplasm, which is in contrast to RP58 that was localized in the nucleus. Interestingly, co-transfection with simiRP58 and RP58 induced changes in the localization patterns of both proteins.
authors.affiliation: Tokyo Metropolitan Institute for Neuroscience, Molecular Physiology, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan.
authors.forename: Akiyo
authors.initials: A
authors.lastname: Takahashi
authors.forename: Shinobu
authors.initials: S
authors.lastname: Hirai
authors.forename: Chiaki
authors.initials: C
authors.lastname: Ohtaka-Maruyama
authors.forename: Akiko
authors.initials: A
authors.lastname: Miwa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hata
authors.forename: Shigeo
authors.initials: S
authors.lastname: Okabe
authors.forename: Haruo
authors.initials: H
authors.lastname: Okado
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D008297:Male; D051379:Mice; D012097:Repressor Proteins / Q000378:metabolism*; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism*; D013737:Testis / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D012097:Repressor Proteins; C520669:Zbtb18 protein, mouse