DNMT1 forms a complex with Rb, E2F1 and HDAC1 and represses transcription from E2F-responsive promoters

Methylation of CpG islands is associated with transcriptional silencing and the formation of nuclease-resistant chromatin structures enriched in hypoacetylated histones. Methyl-CpG-binding proteins, such as MeCP2, provide a link between methylated DNA and hypoacetylated histones by recruiting histone deacetylase, but the mechanisms establishing the methylation patterns themselves are unknown. Whether DNA methylation is always causal for the assembly of repressive chromatin or whether features of transcriptionally silent chromatin might target methyltransferase remains unresolved. Mammalian DNA methyltransferases show little sequence specificity in vitro, yet methylation can be targeted in vivo within chromosomes to repetitive elements, centromeres and imprinted loci. This targeting is frequently disrupted in tumour cells, resulting in the improper silencing of tumour-suppressor genes associated with CpG islands. Here we show that the predominant mammalian DNA methyltransferase, DNMT1, co-purifies with the retinoblastoma (Rb) tumour suppressor gene product, E2F1, and HDAC1 and that DNMT1 cooperates with Rb to repress transcription from promoters containing E2F-binding sites. These results establish a link between DNA methylation, histone deacetylase and sequence-specific DNA binding activity, as well as a growth-regulatory pathway that is disrupted in nearly all cancer cells.

[1]  J. Bender,et al.  An inverted repeat triggers cytosine methylation of identical sequences in Arabidopsis. , 1999, Molecular cell.

[2]  Peter A. Jones,et al.  Cancer-epigenetics comes of age , 1999, Nature Genetics.

[3]  Luke Hughes-Davies,et al.  DNA methyltransferase Dnmt1 associates with histone deacetylase activity , 2000, Nature Genetics.

[4]  Colin A. Johnson,et al.  Transcriptional repression by the methyl-CpG-binding protein MeCP2 involves a histone deacetylase complex , 1998, Nature.

[5]  D. Dean,et al.  Rb Interacts with Histone Deacetylase to Repress Transcription , 1998, Cell.

[6]  D. Haber,et al.  DNA Methyltransferases Dnmt3a and Dnmt3b Are Essential for De Novo Methylation and Mammalian Development , 1999, Cell.

[7]  N. Tommerup,et al.  Chromosome instability and immunodeficiency syndrome caused by mutations in a DNA methyltransferase gene , 1999, Nature.

[8]  H. Ng,et al.  Human DNA-(cytosine-5) methyltransferase-PCNA complex as a target for p21WAF1. , 1997, Science.

[9]  J. Girault,et al.  Histone acetyltransferase activity of CBP is controlled by cycle-dependent kinases and oncoprotein E1A , 1998, Nature.

[10]  T. Hashimshony,et al.  DNA methylation models histone acetylation , 1998, Nature.

[11]  M. Hung,et al.  Drosophila proteins related to vertebrate DNA (5-cytosine) methyltransferases. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[12]  David Garrick,et al.  Repeat-induced gene silencing in mammals , 1998, Nature Genetics.

[13]  M. Surani.  Imprinting and the Initiation of Gene Silencing in the Germ Line , 1998, Cell.

[14]  J. Strouboulis,et al.  Methylated DNA and MeCP2 recruit histone deacetylase to repress transcription , 1998, Nature Genetics.

[15]  S. Kornbluth,et al.  Negative Regulation of DNA Replication by the Retinoblastoma Protein Is Mediated by Its Association with MCM7 , 1998, Molecular and Cellular Biology.

[16]  L. Magnaghi-Jaulin,et al.  Retinoblastoma protein represses transcription by recruiting a histone deacetylase , 1998, Nature.

[17]  H. Leonhardt,et al.  A targeting sequence directs DNA methyltransferase to sites of DNA replication in mammalian nuclei , 1992, Cell.

[18]  Rudolf Jaenisch,et al.  Targeted mutation of the DNA methyltransferase gene results in embryonic lethality , 1992, Cell.

[19]  C. Wijmenga,et al.  The DNMT3B DNA methyltransferase gene is mutated in the ICF immunodeficiency syndrome. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[20]  X. Graña,et al.  Role of the retinoblastoma protein family, pRB, p107 and p130 in the negative control of cell growth , 1998, Oncogene.

[21]  K. Sugamura,et al.  HTLV-I Tax trans-activation and cell growth signaling. , 1997, Leukemia.

[22]  Peter A. Jones,et al.  The Human ARF Cell Cycle Regulatory Gene Promoter Is a CpG Island Which Can Be Silenced by DNA Methylation and Down-Regulated by Wild-Type p53 , 1998, Molecular and Cellular Biology.

[23]  Identification of a mammalian protein that binds specifically to DNA containing methylated CpGs , 1989, Cell.

[24]  J. Herman,et al.  DNA methylation changes in hematologic malignancies: biologic and clinical implications. , 1997, Leukemia.

[25]  K. Robertson,et al.  The human DNA methyltransferases (DNMTs) 1, 3a and 3b: coordinate mRNA expression in normal tissues and overexpression in tumors. , 1999, Nucleic acids research.

[26]  S. Baylin,et al.  Increased cytosine DNA-methyltransferase activity during colon cancer progression. , 1993, Journal of the National Cancer Institute.

[27]  S. Bell,et al.  ORC localization in Drosophila follicle cells and the effects of mutations in dE2F and dDP. , 1999, Genes & development.

[28]  Sushovan Guha,et al.  The retinoblastoma protein and BRG1 form a complex and cooperate to induce cell cycle arrest , 1994, Cell.

[29]  S. S. Smith,et al.  Mechanism of human methyl-directed DNA methyltransferase and the fidelity of cytosine methylation. , 1992, Proceedings of the National Academy of Sciences of the United States of America.