Photobleaching studies reveal that a single amino acid polymorphism is responsible for the differential binding affinities of linker histone subtypes H1.1 and H1.5

Mammals express six major somatic linker histone subtypes, all of which display dynamic binding to chromatin, characterized by transient binding at a given location followed by rapid translocation to a new site. Using photobleaching techniques, we systematically measured the exchange rate of all six...

Full description

Saved in:
Bibliographic Details
Published in:Biology open 2016-03, Vol.5 (3), p.372-380
Main Authors: Flanagan, Thomas W, Files, Jacob K, Casano, Kelsey Rose, George, Eric M, Brown, David T
Format: Article
Language:English
Subjects:
Affinity
Amino acids
Binding
Cell cycle
Chromatin
Fibroblasts
FRAP
Heterogeneity
Histone H1
Histones
Linker histone
Mutagenesis
Photobleaching
Photochemical reactions
Polymorphism
Translocation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Mammals express six major somatic linker histone subtypes, all of which display dynamic binding to chromatin, characterized by transient binding at a given location followed by rapid translocation to a new site. Using photobleaching techniques, we systematically measured the exchange rate of all six mouse H1 subtypes to determine their relative chromatin-binding affinity. Two subtypes, H1.1 and H1.2, display binding affinities that are significantly lower than all other subtypes. Using in vitro mutagenesis, the differences in chromatin-binding affinities between H1.1 (lower binding affinity) and H1.5 (higher binding affinity) were mapped to a single amino acid polymorphism near the junction of the globular and C-terminal domains. Overexpression of H1.5 in density arrested fibroblasts did not affect cell cycle progression after release. By contrast, overexpression of H1.1 resulted in a more rapid progression through G1/S relative to control cells. These results provide structural insights into the proposed functional significance of linker histone heterogeneity.
ISSN:2046-6390
2046-6390
DOI:10.1242/bio.016733