Histone release during transcription: displacement of the two H2A-H2B dimers in the nucleosome is dependent on different levels of transcription-induced positive stress. Biochemistry 2005 Apr 12;44(14):5357-72
Date
04/06/2005Pubmed ID
15807529DOI
10.1021/bi047786oScopus ID
2-s2.0-16844366808 (requires institutional sign-in at Scopus site) 57 CitationsAbstract
Both indirect (transcription-induced stress) and direct effects of polymerase elongation on histone-DNA interactions were studied on closed circular DNA that was either moderately or positively coiled. The templates were reconstituted with (3)H-labeled H2A, H2B, H3, and H4 to form nucleosomes, and transcription was done with T7 RNA polymerase in the presence of a negatively coiled competitor DNA (reconstituted with unlabeled H3 and H4). The first of the two labeled H2A-H2B dimers readily displaced from the highly positively coiled template to the competitor even in the absence of transcription, while the indirect effect of transcription-induced stress was required for the moderately coiled template. The second labeled H2A-H2B dimer required transcription-induced stress for both moderately and highly positively coiled DNA. The displacement of the labeled H3-H4 tetramer also occurred, provided it was associated with an H2A-H2B dimer and a moderately positively coiled DNA. This displacement occurred independent of transcription-induced stress and is likely due to the direct effect of polymerase disruption of histone-DNA interactions. The inclusion of the histone chaperone, NAP1, greatly enhanced the release of both of the two H2A-H2B dimers. These observations are consistent with in vivo observations which indicate that during transcription H2A and H2B are significantly more mobile than H3 and H4 and indicate that transcription-induced positive stress is a likely cause for this selective movement.
Author List
Levchenko V, Jackson B, Jackson VAuthor
Vaughn E. Jackson PhD Professor in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsChickens
Dimerization
Histones
Nucleosomes
Transcription, Genetic
