title: Eukaryotic cytosine methyltransferases.
abstract: Large-genome eukaryotes use heritable cytosine methylation to silence promoters, especially those associated with transposons and imprinted genes. Cytosine methylation does not reinforce or replace ancestral gene regulation pathways but instead endows methylated genomes with the ability to repress specific promoters in a manner that is buffered against changes in the internal and external environment. Recent studies have shown that the targeting of de novo methylation depends on multiple inputs; these include the interaction of repeated sequences, local states of histone lysine methylation, small RNAs and components of the RNAi pathway, and divergent and catalytically inert cytosine methyltransferase homologues that have acquired regulatory roles. There are multiple families of DNA (cytosine-5) methyltransferases in eukaryotes, and each family appears to be controlled by different regulatory inputs. Sequence-specific DNA-binding proteins, which regulate most aspects of gene expression, do not appear to be involved in the establishment or maintenance of genomic methylation patterns.
authors.affiliation: Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA. MGG22@columbia.edu
authors.forename: Mary Grace
authors.initials: MG
authors.lastname: Goll
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Bestor
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000737:chemistry / Q000378:metabolism*; D019175:DNA Methylation; D005057:Eukaryotic Cells; D042822:Genomic Instability; D006801:Humans; D007448:Invertebrates / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D010802:Phylogeny
chemical_list: D004248:DNA (Cytosine-5-)-Methyltransferases