5wvo

Structural highlights

Disease

[DNMT1_HUMAN] Defects in DNMT1 are the cause of hereditary sensory neuropathy type 1E (HSN1E) [MIM:614116]. A neurodegenerative disorder characterized by adult onset of progressive peripheral sensory loss associated with progressive hearing impairment and early-onset dementia.^[1]

Function

[RS27A_HUMAN] Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.^{[2] [3]} Ribosomal protein S27a is a component of the 40S subunit of the ribosome.^{[4] [5]} [DNMT1_HUMAN] Methylates CpG residues. Preferentially methylates hemimethylated DNA. Associates with DNA replication sites in S phase maintaining the methylation pattern in the newly synthesized strand, that is essential for epigenetic inheritance. Associates with chromatin during G2 and M phases to maintain DNA methylation independently of replication. It is responsible for maintaining methylation patterns established in development. DNA methylation is coordinated with methylation of histones. Mediates transcriptional repression by direct binding to HDAC2. In association with DNMT3B and via the recruitment of CTCFL/BORIS, involved in activation of BAG1 gene expression by modulating dimethylation of promoter histone H3 at H3K4 and H3K9.^{[6] [7] [8]}

See Also

• DNA methyltransferase 3D structures

References

1. ↑ Klein CJ, Botuyan MV, Wu Y, Ward CJ, Nicholson GA, Hammans S, Hojo K, Yamanishi H, Karpf AR, Wallace DC, Simon M, Lander C, Boardman LA, Cunningham JM, Smith GE, Litchy WJ, Boes B, Atkinson EJ, Middha S, B Dyck PJ, Parisi JE, Mer G, Smith DI, Dyck PJ. Mutations in DNMT1 cause hereditary sensory neuropathy with dementia and hearing loss. Nat Genet. 2011 Jun;43(6):595-600. Epub 2011 May 1. PMID:21532572 doi:10.1038/ng.830
2. ↑ Huang F, Kirkpatrick D, Jiang X, Gygi S, Sorkin A. Differential regulation of EGF receptor internalization and degradation by multiubiquitination within the kinase domain. Mol Cell. 2006 Mar 17;21(6):737-48. PMID:16543144 doi:S1097-2765(06)00120-1
3. ↑ Komander D. The emerging complexity of protein ubiquitination. Biochem Soc Trans. 2009 Oct;37(Pt 5):937-53. doi: 10.1042/BST0370937. PMID:19754430 doi:10.1042/BST0370937
4. ↑ Huang F, Kirkpatrick D, Jiang X, Gygi S, Sorkin A. Differential regulation of EGF receptor internalization and degradation by multiubiquitination within the kinase domain. Mol Cell. 2006 Mar 17;21(6):737-48. PMID:16543144 doi:S1097-2765(06)00120-1
5. ↑ Komander D. The emerging complexity of protein ubiquitination. Biochem Soc Trans. 2009 Oct;37(Pt 5):937-53. doi: 10.1042/BST0370937. PMID:19754430 doi:10.1042/BST0370937
6. ↑ Vire E, Brenner C, Deplus R, Blanchon L, Fraga M, Didelot C, Morey L, Van Eynde A, Bernard D, Vanderwinden JM, Bollen M, Esteller M, Di Croce L, de Launoit Y, Fuks F. The Polycomb group protein EZH2 directly controls DNA methylation. Nature. 2006 Feb 16;439(7078):871-4. Epub 2005 Dec 14. PMID:16357870 doi:10.1038/nature04431
7. ↑ Pradhan M, Esteve PO, Chin HG, Samaranayke M, Kim GD, Pradhan S. CXXC domain of human DNMT1 is essential for enzymatic activity. Biochemistry. 2008 Sep 23;47(38):10000-9. doi: 10.1021/bi8011725. Epub 2008 Aug, 29. PMID:18754681 doi:10.1021/bi8011725
8. ↑ Sun L, Huang L, Nguyen P, Bisht KS, Bar-Sela G, Ho AS, Bradbury CM, Yu W, Cui H, Lee S, Trepel JB, Feinberg AP, Gius D. DNA methyltransferase 1 and 3B activate BAG-1 expression via recruitment of CTCFL/BORIS and modulation of promoter histone methylation. Cancer Res. 2008 Apr 15;68(8):2726-35. PMID:18413740 doi:68/8/2726
9. ↑ Ishiyama S, Nishiyama A, Saeki Y, Moritsugu K, Morimoto D, Yamaguchi L, Arai N, Matsumura R, Kawakami T, Mishima Y, Hojo H, Shimamura S, Ishikawa F, Tajima S, Tanaka K, Ariyoshi M, Shirakawa M, Ikeguchi M, Kidera A, Suetake I, Arita K, Nakanishi M. Structure of the Dnmt1 Reader Module Complexed with a Unique Two-Mono-Ubiquitin Mark on Histone H3 Reveals the Basis for DNA Methylation Maintenance. Mol Cell. 2017 Oct 19;68(2):350-360.e7. doi: 10.1016/j.molcel.2017.09.037. PMID:29053958 doi:http://dx.doi.org/10.1016/j.molcel.2017.09.037