Coactivator P100 protein enhances STAT6-dependent transcriptional activation but has no effect on STAT1-mediated gene transcription.
The family of STAT proteins consists of seven members that mediate highly specific functions in cytokine signaling. STAT6 is a critical regulator of transcription for interleukin-4 (IL-4)-induced genes. Activation of gene expression involves recruitment of coactivator proteins that function as bridging factors connecting sequence-specific transcription factors to the basal transcription machinery, and as chromatin-modifying enzymes. In this report, we show that the coacitivator p100 protein can interact with STAT6 through its SN domain both in vivo and in vitro, resulting in enhancement of STAT6-mediated gene transcriptional acitivation. Consistent with our previous reports, we identified intracellular localization of p100 and STAT-6 by confocal microscopy examined in response to IL-4. Moreover, in consideration of STAT molecules sharing significant homology in structure and function, we detected whether p100 can associate with STAT-1. In conclusion, this study found no evidence that p100 functions as a transcriptional coactivator for STAT1-dependent gene regulation.
Department of Immunology, Tianjin Medical University, Tianjin, People's Republic of China.
Xinting
X
Wang
Xin
X
Liu
Jianfei
J
Fang
Yanxin
Y
Lu
Jinyan
J
He
Xuyang
X
Yao
Zhi
Z
Yao
Jie
J
Yang
D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004720:Endonucleases; D006367:HeLa Cells; D006801:Humans; D015847:Interleukin-4 / Q000378:metabolism / Q000494:pharmacology; D018613:Microscopy, Confocal; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000235:genetics; D050794:STAT1 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D050800:STAT6 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics*
D009687:Nuclear Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D015847:Interleukin-4; D004720:Endonucleases; C095221:SND1 protein, human