| Structural highlights
Disease
[MLL1_HUMAN] Defects in MLL are the cause of Wiedemann-Steiner syndrome (WDSTS) [MIM:605130]. A syndrome characterized by hairy elbows (hypertrichosis cubiti), intellectual disability, a distinctive facial appearance, and short stature. Facial characteristics include long eyelashes, thick or arched eyebrows with a lateral flare, and downslanting and vertically narrow palpebral fissures.[1] [2] Note=Chromosomal aberrations involving MLL are a cause of acute leukemias. Translocation t(1;11)(q21;q23) with MLLT11/AF1Q; translocation t(3;11)(p21;q23) with NCKIPSD/AF3p21; translocation t(3,11)(q25,q23) with GMPS; translocation t(4;11)(q21;q23) with AFF1/MLLT2/AF4; insertion ins(5;11)(q31;q13q23) with AFF4/AF5Q31; translocation t(5;11)(q12;q23) with AF5-alpha/CENPK; translocation t(6;11)(q27;q23) with MLLT4/AF6; translocation t(9;11)(p22;q23) with MLLT3/AF9; translocation t(10;11)(p11.2;q23) with ABI1; translocation t(10;11)(p12;q23) with MLLT10/AF10; t(11;15)(q23;q14) with CASC5 and ZFYVE19; translocation t(11;17)(q23;q21) with MLLT6/AF17; translocation t(11;19)(q23;p13.3) with ELL; translocation t(11;19)(q23;p13.3) with MLLT1/ENL; translocation t(11;19)(q23;p23) with GAS7; translocation t(X;11)(q13;q23) with FOXO4/AFX1. Translocation t(3;11)(q28;q23) with LPP. Translocation t(10;11)(q22;q23) with TET1. Translocation t(9;11)(q34;q23) with DAB2IP. Translocation t(4;11)(p12;q23) with FRYL. Fusion proteins MLL-MLLT1, MLL-MLLT3 and MLL-ELL interact with PPP1R15A and, on the contrary to unfused MLL, inhibit PPP1R15A-induced apoptosis.[3] Note=A chromosomal aberration involving MLL may be a cause of chronic neutrophilic leukemia. Translocation t(4;11)(q21;q23) with SEPT11.[4]
Function
[MLL1_HUMAN] Histone methyltransferase that plays an essential role in early development and hematopoiesis. Catalytic subunit of the MLL1/MLL complex, a multiprotein complex that mediates both methylation of 'Lys-4' of histone H3 (H3K4me) complex and acetylation of 'Lys-16' of histone H4 (H4K16ac). In the MLL1/MLL complex, it specifically mediates H3K4me, a specific tag for epigenetic transcriptional activation. Has weak methyltransferase activity by itself, and requires other component of the MLL1/MLL complex to obtain full methyltransferase activity. Has no activity toward histone H3 phosphorylated on 'Thr-3', less activity toward H3 dimethylated on 'Arg-8' or 'Lys-9', while it has higher activity toward H3 acetylated on 'Lys-9'. Required for transcriptional activation of HOXA9. Promotes PPP1R15A-induced apoptosis.[5] [6] [7] [8]
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
The MLL1 gene is a frequent target for recurrent chromosomal translocations, resulting in transformation of hematopoietic precursors into leukemia stem cells. Here, we report on structure-function studies that elucidate molecular events in MLL1 binding of histone H3K4me3/2 marks and recruitment of the cyclophilin CyP33. CyP33 contains a PPIase and a RRM domain and regulates MLL1 function through HDAC recruitment. We find that the PPIase domain of CyP33 regulates the conformation of MLL1 through proline isomerization within the PHD3-Bromo linker, thereby disrupting the PHD3-Bromo interface and facilitating binding of the MLL1-PHD3 domain to the CyP33-RRM domain. H3K4me3/2 and CyP33-RRM target different surfaces of MLL1-PHD3 and can bind simultaneously to form a ternary complex. Furthermore, the MLL1-CyP33 interaction is required for repression of HOXA9 and HOXC8 genes in vivo. Our results highlight the role of PHD3-Bromo cassette as a regulatory platform, orchestrating MLL1 binding of H3K4me3/2 marks and cyclophilin-mediated repression through HDAC recruitment.
Pro isomerization in MLL1 PHD3-bromo cassette connects H3K4me readout to CyP33 and HDAC-mediated repression.,Wang Z, Song J, Milne TA, Wang GG, Li H, Allis CD, Patel DJ Cell. 2010 Jun 25;141(7):1183-94. Epub 2010 Jun 10. PMID:20541251[9]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Adler HT, Chinery R, Wu DY, Kussick SJ, Payne JM, Fornace AJ Jr, Tkachuk DC. Leukemic HRX fusion proteins inhibit GADD34-induced apoptosis and associate with the GADD34 and hSNF5/INI1 proteins. Mol Cell Biol. 1999 Oct;19(10):7050-60. PMID:10490642
- ↑ Jones WD, Dafou D, McEntagart M, Woollard WJ, Elmslie FV, Holder-Espinasse M, Irving M, Saggar AK, Smithson S, Trembath RC, Deshpande C, Simpson MA. De novo mutations in MLL cause Wiedemann-Steiner syndrome. Am J Hum Genet. 2012 Aug 10;91(2):358-64. doi: 10.1016/j.ajhg.2012.06.008. Epub, 2012 Jul 12. PMID:22795537 doi:10.1016/j.ajhg.2012.06.008
- ↑ Adler HT, Chinery R, Wu DY, Kussick SJ, Payne JM, Fornace AJ Jr, Tkachuk DC. Leukemic HRX fusion proteins inhibit GADD34-induced apoptosis and associate with the GADD34 and hSNF5/INI1 proteins. Mol Cell Biol. 1999 Oct;19(10):7050-60. PMID:10490642
- ↑ Adler HT, Chinery R, Wu DY, Kussick SJ, Payne JM, Fornace AJ Jr, Tkachuk DC. Leukemic HRX fusion proteins inhibit GADD34-induced apoptosis and associate with the GADD34 and hSNF5/INI1 proteins. Mol Cell Biol. 1999 Oct;19(10):7050-60. PMID:10490642
- ↑ Adler HT, Chinery R, Wu DY, Kussick SJ, Payne JM, Fornace AJ Jr, Tkachuk DC. Leukemic HRX fusion proteins inhibit GADD34-induced apoptosis and associate with the GADD34 and hSNF5/INI1 proteins. Mol Cell Biol. 1999 Oct;19(10):7050-60. PMID:10490642
- ↑ Nakamura T, Mori T, Tada S, Krajewski W, Rozovskaia T, Wassell R, Dubois G, Mazo A, Croce CM, Canaani E. ALL-1 is a histone methyltransferase that assembles a supercomplex of proteins involved in transcriptional regulation. Mol Cell. 2002 Nov;10(5):1119-28. PMID:12453419
- ↑ Dou Y, Milne TA, Tackett AJ, Smith ER, Fukuda A, Wysocka J, Allis CD, Chait BT, Hess JL, Roeder RG. Physical association and coordinate function of the H3 K4 methyltransferase MLL1 and the H4 K16 acetyltransferase MOF. Cell. 2005 Jun 17;121(6):873-85. PMID:15960975 doi:10.1016/j.cell.2005.04.031
- ↑ 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
- ↑ Wang Z, Song J, Milne TA, Wang GG, Li H, Allis CD, Patel DJ. Pro isomerization in MLL1 PHD3-bromo cassette connects H3K4me readout to CyP33 and HDAC-mediated repression. Cell. 2010 Jun 25;141(7):1183-94. Epub 2010 Jun 10. PMID:20541251 doi:10.1016/j.cell.2010.05.016
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