| Structural highlights
Function
[MAD1_HUMAN] Transcriptional repressor. MAD binds with MAX to form a sequence-specific DNA-binding protein complex which recognizes the core sequence 5'-CAC[GA]TG-3'. MAD thus antagonizes MYC transcriptional activity by competing for MAX. [SIN3A_MOUSE] Acts as a transcriptional repressor. Corepressor for REST. Interacts with MXI1 to repress MYC responsive genes and antagonize MYC oncogenic activities. Also interacts with MXD1-MAX heterodimers to repress transcription by tethering SIN3A to DNA. Acts cooperatively with OGT to repress transcription in parallel with histone deacetylation.[1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Recruitment of the histone deacetylase (HDAC)-associated Sin3 corepressor is an obligatory step in many eukaryotic gene silencing pathways. Here we show that HBP1, a cell cycle inhibitor and regulator of differentiation, represses transcription in a HDAC/Sin3-dependent manner by targeting the mammalian Sin3A (mSin3A) PAH2 domain. HBP1 is unrelated to the Mad1 repressor for which high-resolution structures in complex with PAH2 have been described. We show that like Mad1, the HBP1 transrepression domain binds through a helical structure to the hydrophobic cleft of mSin3A PAH2. Notably, the HBP1 helix binds PAH2 in a reversed orientation relative to Mad1 and, equally unexpectedly, this is correlated with a chain reversal of the minimal Sin3 interaction motifs. These results not only provide insights into how multiple, unrelated transcription factors recruit the same coregulator, but also have implications for how sequence similarity searches are conducted.
HBP1 and Mad1 repressors bind the Sin3 corepressor PAH2 domain with opposite helical orientations.,Swanson KA, Knoepfler PS, Huang K, Kang RS, Cowley SM, Laherty CD, Eisenman RN, Radhakrishnan I Nat Struct Mol Biol. 2004 Aug;11(8):738-46. Epub 2004 Jul 4. PMID:15235594[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Rao G, Alland L, Guida P, Schreiber-Agus N, Chen K, Chin L, Rochelle JM, Seldin MF, Skoultchi AI, DePinho RA. Mouse Sin3A interacts with and can functionally substitute for the amino-terminal repression of the Myc antagonist Mxi1. Oncogene. 1996 Mar 7;12(5):1165-72. PMID:8649810
- ↑ Ayer DE, Lawrence QA, Eisenman RN. Mad-Max transcriptional repression is mediated by ternary complex formation with mammalian homologs of yeast repressor Sin3. Cell. 1995 Mar 10;80(5):767-76. PMID:7889570
- ↑ Grimes JA, Nielsen SJ, Battaglioli E, Miska EA, Speh JC, Berry DL, Atouf F, Holdener BC, Mandel G, Kouzarides T. The co-repressor mSin3A is a functional component of the REST-CoREST repressor complex. J Biol Chem. 2000 Mar 31;275(13):9461-7. PMID:10734093
- ↑ Swanson KA, Knoepfler PS, Huang K, Kang RS, Cowley SM, Laherty CD, Eisenman RN, Radhakrishnan I. HBP1 and Mad1 repressors bind the Sin3 corepressor PAH2 domain with opposite helical orientations. Nat Struct Mol Biol. 2004 Aug;11(8):738-46. Epub 2004 Jul 4. PMID:15235594 doi:10.1038/nsmb798
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