We have isolated and characterized a gene, His1-3, encoding a structurally divergent linker histone in Arabidopsis thaliana. Southern and northern hybridization data indicate that A. thaliana expresses three single-copy linker histone genes, each encoding a structurally distinct variant, H1-3 is a considerably smaller protein (167 amino acids with a mass of 19.0 kDa) than any other described linker histone from higher eukaryotes. We examined the expression of His1-3 at the RNA and protein levels and found that it is induced specifically by water stress. In contrast, expression of His1-1, His1-2 and His4 appear unaffected by water stress. Furthermore, the primary structure of the protein possesses distinct characteristics that are shared with another drought-inducible linker histone. H1-D, isolated from Lycopersicon pennellii. Based on structural characteristics of the deduced protein and its inducible expression, we hypothesize that H1-3 and H1-D are linker histone variants that have specialized roles in the structure and function of plant chromatin and therefore they can be considered to be members of a unique subclass of plant histones. Immunoblotting with an antibody produced against a short polypeptide in the conserved domain of this subtype indicates that similar proteins may exist in other plants.
|Original language||English (US)|
|Number of pages||13|
|Journal||Plant molecular biology|
|State||Published - Jul 1997|
Bibliographical noteFunding Information:
We thank the Arabidopsis Biological Resource Center for providing us with the cDNA used to obtain His1-3, several other cDNAs used as probes, as well as the mutants used in this paper. This research was funded in part by a grant from the USDA (95-37301-1800).
- Abscisic acid
- Environmental stress
- Gene family
- Linker histone variants