Co-operative interactions of oligonucleosomal DNA with the H1e histone variant and its poly(ADP-ribosyl)ated isoform.
H1 histone somatic variants from L929 mouse fibroblasts were purified by reverse-phase HPLC. We analysed the ability of each H1 histone variant to allow the H1-H1 interactions that are essential for the formation of the higher levels of chromatin structure, and we investigated the role played by the poly(ADP-ribosyl)ation process. Cross-linking analysis showed that H1e is the only somatic variant which, when bound to DNA, is able to produce H1-H1 polymers; the size of polymers was decreased when H1e was enriched in its poly(ADP-ribosyl)ated isoform. Measurement of the methyl-accepting ability in native nuclei compared with nuclei in which poly(ADP-ribosyl)ation was induced showed that the poly(ADP-ribosyl)ated H1 histone had not been removed from linker regions, in spite of its different interaction with DNA.
D'erme
M
M
Dipartimento di Scienze Biochimiche, A. Rossi Fanelli, Università di Roma La Sapienza, Italy.
Zardo
G
G
Reale
A
A
Caiafa
P
P
D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts; D006657:Histones / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008745:Methylation; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D051379:Mice; D009153:Mutagens / Q000494:pharmacology; D009707:Nucleosomes / Q000378:metabolism*; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*
D002843:Chromatin; D006657:Histones; D009153:Mutagens; D009707:Nucleosomes; D008769:Methylnitronitrosoguanidine; D011064:Poly Adenosine Diphosphate Ribose; D004247:DNA