| Structural highlights
Function
[WDR5_HUMAN] Contributes to histone modification. May position the N-terminus of histone H3 for efficient trimethylation at 'Lys-4'. As part of the MLL1/MLL complex it is involved in methylation and dimethylation at 'Lys-4' of histone H3. H3 'Lys-4' methylation represents a specific tag for epigenetic transcriptional activation. As part of the NSL complex it may be involved in acetylation of nucleosomal histone H4 on several lysine residues. May regulate osteoblasts differentiation.[1] [2] [3] [4] [5] [SET1B_HUMAN] Histone methyltransferase that specifically methylates 'Lys-4' of histone H3, when part of the SET1 histone methyltransferase (HMT) complex, but not if the neighboring 'Lys-9' residue is already methylated. H3 'Lys-4' methylation represents a specific tag for epigenetic transcriptional activation. The non-overalpping localization with SETD1A suggests that SETD1A and SETD1B make non-redundant contributions to the epigenetic control of chromatin structure and gene expression. Specifically tri-methylates 'Lys-4' of histone H3 in vitro.
Publication Abstract from PubMed
Translocations and amplifications of the mixed lineage leukemia-1 (MLL1) gene are associated with aggressive myeloid and lymphocytic leukemias in humans. MLL1 is a member of the SET1 family of histone H3 lysine 4 (H3K4) methyltransferases, which are required for transcription of genes involved in hematopoiesis and development. MLL1 associates with a subcomplex containing WDR5, RbBP5, Ash2L, and DPY-30 (WRAD), which together form the MLL1 core complex that is required for sequential mono- and dimethylation of H3K4. We previously demonstrated that WDR5 binds the conserved WDR5 interaction (Win) motif of MLL1 in vitro, an interaction that is required for the H3K4 dimethylation activity of the MLL1 core complex. In this investigation, we demonstrate that arginine 3765 of the MLL1 Win motif is required to co-immunoprecipitate WRAD from mammalian cells, suggesting that the WDR5-Win motif interaction is important for the assembly of the MLL1 core complex in vivo. We also demonstrate that peptides that mimic SET1 family Win motif sequences inhibit H3K4 dimethylation by the MLL1 core complex with varying degrees of efficiency. To understand the structural basis for these differences, we determined structures of WDR5 bound to six different naturally occurring Win motif sequences at resolutions ranging from 1.9 to 1.2 A. Our results reveal that binding energy differences result from interactions between non-conserved residues C-terminal to the Win motif and to a lesser extent from subtle variation of residues within the Win motif. These results highlight a new class of methylation inhibitors that may be useful for the treatment of MLL1-related malignancies.
Structural basis for WDR5 interaction (Win) motif recognition in human SET1 family histone methyltransferases.,Dharmarajan V, Lee JH, Patel A, Skalnik DG, Cosgrove MS J Biol Chem. 2012 Aug 10;287(33):27275-89. Epub 2012 Jun 3. PMID:22665483[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Patel A, Dharmarajan V, Vought VE, Cosgrove MS. On the mechanism of multiple lysine methylation by the human mixed lineage leukemia protein-1 (MLL1) core complex. J Biol Chem. 2009 Sep 4;284(36):24242-56. Epub 2009 Jun 25. PMID:19556245 doi:M109.014498
- ↑ Guelman S, Kozuka K, Mao Y, Pham V, Solloway MJ, Wang J, Wu J, Lill JR, Zha J. The double-histone-acetyltransferase complex ATAC is essential for mammalian development. Mol Cell Biol. 2009 Mar;29(5):1176-88. doi: 10.1128/MCB.01599-08. Epub 2008 Dec, 22. PMID:19103755 doi:10.1128/MCB.01599-08
- ↑ Cai Y, Jin J, Swanson SK, Cole MD, Choi SH, Florens L, Washburn MP, Conaway JW, Conaway RC. Subunit composition and substrate specificity of a MOF-containing histone acetyltransferase distinct from the male-specific lethal (MSL) complex. J Biol Chem. 2010 Feb 12;285(7):4268-72. doi: 10.1074/jbc.C109.087981. Epub 2009 , Dec 14. PMID:20018852 doi:10.1074/jbc.C109.087981
- ↑ Han Z, Guo L, Wang H, Shen Y, Deng XW, Chai J. Structural basis for the specific recognition of methylated histone H3 lysine 4 by the WD-40 protein WDR5. Mol Cell. 2006 Apr 7;22(1):137-44. PMID:16600877 doi:10.1016/j.molcel.2006.03.018
- ↑ Couture JF, Collazo E, Trievel RC. Molecular recognition of histone H3 by the WD40 protein WDR5. Nat Struct Mol Biol. 2006 Aug;13(8):698-703. Epub 2006 Jul 9. PMID:16829960 doi:10.1038/nsmb1116
- ↑ Dharmarajan V, Lee JH, Patel A, Skalnik DG, Cosgrove MS. Structural basis for WDR5 interaction (Win) motif recognition in human SET1 family histone methyltransferases. J Biol Chem. 2012 Aug 10;287(33):27275-89. Epub 2012 Jun 3. PMID:22665483 doi:http://dx.doi.org/10.1074/jbc.M112.364125
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