Strom R, Santoro R, D'Erme M, Mastrantonio S, Reale A, Marenzi S, Zardo G, Caiafa P
Department of Human Biopathology, University of Rome, La Sapienza, Italy.
Gene. 1995 May 19;157(1-2):253-6. doi: 10.1016/0378-1119(95)91236-s.
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.
