Comparative functional analysis of rat TGF-beta1 and Xenopus laevis TGF-beta5 promoters suggest differential regulations.
We have carried out a comparative functional analysis of the rat TGF-beta1 and Xenopus laevis TGF-beta5 promoters across several mammalian and amphibian cell lines. Progressive deletion constructs of both the promoters have been made using a PCR based approach and the basal promoter activities studied in Xenopus tadpole cell line (XTC), Xenopus adult kidney fibroblast cell line (A6), human hepatoma cell line (HepG2), normal rat kidney cell line (NRK), and Chinese hamster ovary cell line (CHO). Data suggests that the basal promoter activity of TGF-beta1 is low as compared to TGF-beta5 promoter in XTC cells but comparable in A6 cells, while TGF-beta5 promoter shows nearly negligible activity as compared to TGF-beta5 promoter in all the tested mammalian cell lines. Moreover, TGF-beta5 promoter is found to be repressed in XTC cells on treatment with TGF-beta5 protein. Thus, the regulation of TGF-beta1 and TGF-beta5 promoters is distinct in amphibian and mammalian species. We therefore suggest that contrary to the suggested functional equivalence of TGF-beta1 and TGF-beta5 proteins, TGF-beta1 and TGF-beta5 genes have distinct functions in their respective species.
Goswami
Moloy T
MT
Department of Molecular Reproduction Development and Genetics, Indian Institute of Science, Bangalore 560 012, India.
Desai
Kartiki V
KV
Kondaiah
Paturu
P
D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D005786:Gene Expression Regulation; D006801:Humans; D011401:Promoter Regions, Genetic; D051381:Rats / Q000235:genetics*; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism; D053773:Transforming Growth Factor beta1; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000378:metabolism*
C404602:TGF-beta5 protein, Xenopus laevis; C508960:TGFB1 protein, human; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D029867:Xenopus Proteins