Specific variants of H1 histone regulate CpG methylation in eukaryotic DNA.
Upon HPLC fractionation of human placenta or calf thymus H1 histone preparations, only some fractions enriched in the H1e-c variants were able to exert a severe inhibition on in vitro enzymatic DNA methylation. These fractions, though similar to the other variants in interacting with genomic DNA, were also the only ones which could bind CpG-rich ds-oligodeoxyribonucleotides (oligos). Both the 6-CpG ds-oligo and the DNA purified from chromatin fractions enriched in 'CpG islands' were good competitors for the binding of H1e-c to the 6meCpG ds-oligo. This ability to bind any DNA sequence and to suppress the enzymatic methylation in any sequence containing CpG dinucleotides suggests, for these particular H1 variants, a possible role in maintaining CpG island DNA and linker DNA at low methylation levels.
Strom
R
R
Department of Human Biopathology, University of Rome, La Sapienza, Italy.
Santoro
R
R
D'Erme
M
M
Mastrantonio
S
S
Reale
A
A
Marenzi
S
S
Zardo
G
G
Caiafa
P
P
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D015226:Dinucleoside Phosphates; D005260:Female; D014644:Genetic Variation; D006657:Histones / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D008745:Methylation; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D013950:Thymus Gland / Q000378:metabolism
D002843:Chromatin; D004247:DNA; D015226:Dinucleoside Phosphates; D006657:Histones; D009838:Oligodeoxyribonucleotides; C015772:CpG dinucleotide