Molecular cloning of a novel human I-mfa domain-containing protein that differently regulates human T-cell leukemia virus type I and HIV-1 expression.

摘要: Regulation of viral genome expression is the result complex cooperation between proteins and host cell factors. We report here characterization a novel cellular factor sharing homology with specific cysteine-rich C-terminal domain basic helix-loop-helix repressor protein I-mfa. The synthesis this new factor, called HIC for Human I-mfa domain-Containing protein, controlled at translational level by two different codons, an ATG upstream non-ATG initiator, allowing production isoforms, p32 p40, respectively. show that isoforms present subcellular localizations, being mainly distributed throughout cytoplasm, whereas p40 targeted to nucleolus. Moreover, in trying understand function HIC, we have found both stimulate T-cells luciferase reporter gene driven human T-cell leukemia virus type I-long terminal repeat presence transactivator Tax. demonstrate mutagenesis I-mfa-like involved regulation. Finally, also able down-regulate from immunodeficiency 1-long induced Tat. From these results, propose represent members family regulating characterized particular domain.