1: Int Immunol. 2003 Apr;15(4):467-75. 

MHC class II enhanceosome: how is the class II transactivator recruited to
DNA-bound activators?

Jabrane-Ferrat N, Nekrep N, Tosi G, Esserman L, Peterlin BM.

Department of Surgery and Comprehensive Cancer Center, University of California
San Francisco, CA 94115-0703, USA.

MHC class II (MHCII) determinants play a crucial role in the immune response by
presenting antigenic peptides to T cells. Their expression is controlled from
compact promoters at the transcriptional level. Pre-assembled regulatory factor
X (RFX) and nuclear factor Y (NFY) complexes form a platform on DNA. The class
II transactivator (CIITA) can then be recruited through multiple protein-protein
interactions. In this report, we defined domains of CIITA that are responsible
for its interactions with these DNA-bound factors. Furthermore, using
DNA-affinity precipitation, we demonstrated that although CIITA binds at least
five activators, RFX5, RFXAP, RFXANK/B, NFYB and NFYC, its assembly on the
promoter requires the addition of nuclear extracts. We conclude that not only
does the platform bind DNA via multiple, spatially constrained nteractions, but
that it can recruit only modified and/or complexed CIITA to MHCII promoters.

PMID: 12663676 [PubMed - indexed for MEDLINE]


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