In vitro induction of H1-H1 histone cross-linking by adenosine diphosphate-ribose polymers.
It is well-known that H1-H1 interactions are very important for the induction of 30 nm chromatin fiber and that, among all posttranslational modifications, poly(ADP-ribosyl)ation is one of those capable of modifying chromatin structure, mainly through H1 histone. As this protein can undergo both covalent and noncovalent modifications by poly(ADP-ribosyl)ation, our aim was to investigate whether and how ADP-ribose polymers, by themselves, are able to affect the formation of H1-H1 oligomers, which are normally present in a condensed chromatin structure. The results obtained in our in vitro experimental system indicate that ADP-ribose polymers are involved in chromatin decondensation. This conclusion was reached as the result of two different observations: (a) H1 histone molecules can be hosted in clusters on ADP-ribose polymers, as shown by their ability to be chemically cross-linked, and (b) H1 histone has a higher affinity for ADP-ribose polymers than for DNA; ADP-ribose polymers compete, in fact, with DNA for H1 histone binding.
Reale
A
A
Department of Cellular Biotechnologies and Haematology, University of Rome "La Sapienza", Rome, Italy.
Malanga
M
M
Zardo
G
G
Strom
R
R
Scovassi
A I
AI
Farina
B
B
Caiafa
P
P
D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D006657:Histones / Q000737:chemistry* / Q000378:metabolism*; D066298:In Vitro Techniques; D051379:Mice; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism / Q000494:pharmacology*; D020836:Protein Structure, Quaternary
D003432:Cross-Linking Reagents; D006657:Histones; D011064:Poly Adenosine Diphosphate Ribose; D004247:DNA