| Structural highlights
Disease
AF9_HUMAN A chromosomal aberration involving MLLT3 is associated with acute leukemias. Translocation t(9;11)(p22;q23) with KMT2A/MLL1. The result is a rogue activator protein.
Function
AF9_HUMAN Component of the super elongation complex (SEC), a complex required to increase the catalytic rate of RNA polymerase II transcription by suppressing transient pausing by the polymerase at multiple sites along the DNA.[1] [2]
Publication Abstract from PubMed
The MLL gene is a common target of chromosomal translocations found in human leukemia. MLL-fusion leukemia has a consistently poor outcome. One of the most common translocation partners is AF9 (MLLT3). MLL-AF9 recruits DOT1L, a histone 3 lysine 79 methyltransferase (H3K79me1/me2/me3), leading to aberrant gene transcription. We show that DOT1L has three AF9 binding sites and present the nuclear magnetic resonance (NMR) solution structure of a DOT1L-AF9 complex. We generate structure-guided point mutations and find that they have graded effects on recruitment of DOT1L to MLL-AF9. Chromatin immunoprecipitation sequencing (ChIP-seq) analyses of H3K79me2 and H3K79me3 show that graded reduction of the DOT1L interaction with MLL-AF9 results in differential loss of H3K79me2 and me3 at MLL-AF9 target genes. Furthermore, the degree of DOT1L recruitment is linked to the level of MLL-AF9 hematopoietic transformation.
Degree of Recruitment of DOT1L to MLL-AF9 Defines Level of H3K79 Di- and Tri-methylation on Target Genes and Transformation Potential.,Kuntimaddi A, Achille NJ, Thorpe J, Lokken AA, Singh R, Hemenway CS, Adli M, Zeleznik-Le NJ, Bushweller JH Cell Rep. 2015 May 5;11(5):808-20. doi: 10.1016/j.celrep.2015.04.004. Epub 2015, Apr 23. PMID:25921540[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Lin C, Smith ER, Takahashi H, Lai KC, Martin-Brown S, Florens L, Washburn MP, Conaway JW, Conaway RC, Shilatifard A. AFF4, a component of the ELL/P-TEFb elongation complex and a shared subunit of MLL chimeras, can link transcription elongation to leukemia. Mol Cell. 2010 Feb 12;37(3):429-37. doi: 10.1016/j.molcel.2010.01.026. PMID:20159561 doi:10.1016/j.molcel.2010.01.026
- ↑ He N, Liu M, Hsu J, Xue Y, Chou S, Burlingame A, Krogan NJ, Alber T, Zhou Q. HIV-1 Tat and host AFF4 recruit two transcription elongation factors into a bifunctional complex for coordinated activation of HIV-1 transcription. Mol Cell. 2010 May 14;38(3):428-38. doi: 10.1016/j.molcel.2010.04.013. PMID:20471948 doi:10.1016/j.molcel.2010.04.013
- ↑ Kuntimaddi A, Achille NJ, Thorpe J, Lokken AA, Singh R, Hemenway CS, Adli M, Zeleznik-Le NJ, Bushweller JH. Degree of Recruitment of DOT1L to MLL-AF9 Defines Level of H3K79 Di- and Tri-methylation on Target Genes and Transformation Potential. Cell Rep. 2015 May 5;11(5):808-20. doi: 10.1016/j.celrep.2015.04.004. Epub 2015, Apr 23. PMID:25921540 doi:http://dx.doi.org/10.1016/j.celrep.2015.04.004
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