Open AccessEffects of Histone Tail Domains on the Rate of Transcriptional Elongation through a Nucleosome
Author(s) -
Reine U. Protacio,
G. Li,
Peggy T. Lowary,
Jonathan Widom
Publication year - 2000
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.20.23.8866-8878.2000
Subject(s) - biology , nucleosome , rna polymerase ii , histone octamer , histone , elongation , microbiology and biotechnology , polymerase , transcription (linguistics) , transcription factor ii d , dna , rna polymerase , biophysics , genetics , gene , rna , gene expression , promoter , materials science , ultimate tensile strength , metallurgy , linguistics , philosophy
The N-terminal tail domains of the core histones play important roles in gene regulation, but the exact mechanisms through which they act are not known. Recent studies suggest that the tail domains may influence the ability of RNA polymerase to elongate through the nucleosomal DNA and, thus, that posttranslational modification of the tail domains may provide a control point for gene regulation through effects on the elongation rate. We take advantage of an experimental system that uses bacteriophage T7 RNA polymerase as a probe for aspects of nucleosome transcription that are dominated by the properties of nucleosomes themselves. With this system, experiments can analyze the synchronous, real-time, single-passage transcription on the nucleosomal template. Here, we use this system to directly test the hypothesis that the tail domains may influence the “elongatability” of nucleosomal DNA and to identify which of the tail domains may contribute to this. The results show that the tail domains strongly influence the rate of elongation and suggest that the effect is dominated by the N-terminal domains of the (H3-H4)2 tetramer. They further imply that tail-mediated octamer transfer is not essential for elongation through the nucleosome. Acetylation of the tail domains leads to effects on elongation that are similar to those arising from complete removal of the tail domains.