Characterization of functional domains of human p100 protein interacting with signal transducer and activator of transcription-6 (STAT-6)

In the present study, the interaction of human p100 protein with signal transducer and activator of transcription-6 (STAT-6) was investigated. It was proved that the staphylococcal nuclease (SN)-like and tudor (TD) domains containing in p100 protein acting as a adaptor to recruit STAT-6 to the basal transcription machinery, enhanced the STAT-6 mediated transcription activity. The interaction between STAT-6 and the p100 protein was mediated by the full-length of the SN-like domain, whereas individual fragments of SN-like domain showed no binding activity to STAT-6. In line with these results, the SN-like domain was directly engaged in the enhancement of STAT-6 mediated activation of gene transcription in vivo. Yet the TD domain had no ability to increase the transcription activation, but it was still required for the sufficient activation of transcription.