Bo Gao, Wei Xu, Linmao Zhong, Qilin Zhang, Ya Su, Sidong Xiong
Department of Immunology, Institute for Immunobiology, Shanghai Medical College of Fudan University, Shanghai, PR China.
European journal of immunology 2013 AugTripartite motif (TRIM) 22 plays an important role in IFN-mediated antiviral activity. We previously demonstrated that IFN regulatory factor-1 (IRF-1) was crucial for constitutive and IFN-induced TRIM22 expression via binding to a special cis-element named 5' extended IFN-stimulating response element. Here, we further investigate the molecular mechanisms of TRIM22 with a focus on the co-activators of IRF-1. Using an in vitro DNA affinity binding assay and an in vivo chromatin immunoprecipitation assay, we found that IFN-γ stimulation significantly enhanced the binding of p300 and p300/CBP-associated factor, but not other co-activators such as general control nondepressible 5, steroid receptor co-activator-1, and activator of thyroid and retinoic, to the 5' extended IFN-stimulating response element containing TRIM22 promoter region together with IRF-1. Overexpression and knockdown analysis demonstrated that it was p300, but not p300/CBP-associated factor, that functioned as a transcriptional co-activator of IRF-1 in IFN-γ induction of TRIM22. We further show that p300 contributed to both IFN-γ- and IRF-1-mediated TRIM22 transcription independent of its histone acetyltransferase activity, however, it was required for the recruitment of RNA polymerase II to TRIM22 promoter region. These data indicate that p300 plays a critical role in IFN-γ-induced TRIM22 expression via recruiting RNA polymerase II to the TRIM22 promoter, and might serve as a bridge between IRF-1 and the basal transcriptional apparatus in TRIM22 induction. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Bo Gao, Wei Xu, Linmao Zhong, Qilin Zhang, Ya Su, Sidong Xiong. p300, but not PCAF, collaborates with IRF-1 in stimulating TRIM22 expression independently of its histone acetyltransferase activity. European journal of immunology. 2013 Aug;43(8):2174-84
PMID: 23670564
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