Mapping the transactivation domain of the Oct-6 POU transcription factor.

The POU transcription factor Oct-6 is expressed in embryonic stem cells, glial progenitor cells and in a restricted set of neurons in the CNS. The protein has been shown to act as a transactivator as well as a repressor. Here we show that the Oct-6 protein activates transcription from three different promoters in HeLa cells. The ability to activate a minimal tk promoter via a multimerized IgH enhancer octamer motif relies on a domain within the aminoterminal third of the protein. Parts of this domain can be deleted without abolishing transactivation, suggesting that there is functional redundancy within this region. The transactivation domain of the Oct-6 protein is different from other described activation domains in that it is highly glycine and alanine rich.