|Kim, Jong Heon|
Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/25/2008
Publication Date: 2/1/2009
Publication URL: http://www3.interscience.wiley.com/cgi-bin/fulltext/121454847/PDFSTART
Citation: Blanvillain, R., Kim, J., Lima, A., Ow, D.W. 2009. OXIDATIVE STRESS 3 is a chromatin-associated factor involved in tolerance to heavy metals and oxidative stress. Plant Journal. 57(4):654-665. Interpretive Summary: This paper describes OXS3, a protein involved in plant stress tolerance and localizes to discrete parts of plant chromosomes. OXS3 belongs to a family of proteins that share a highly conserved domain corresponding to a putative N-acetyltransferase or thioltransferase catalytic site. This domain is needed for the protein to mediate stress tolerance. We propose that OXS3 might act as a chromatin-remodeling factor for the stress response, such as by making DNA more accessible through adding acetyl groups to histones, the structural proteins that DNA wraps around.
Technical Abstract: A cDNA expression library from Brassica juncea was introduced into the fission yeast Schizosaccharomyces pombe to select for transformants tolerant to cadmium. Transformants expressing OXIDATIVE STRESS 3 (OXS3) or OXS3-Like cDNA exhibited enhanced tolerance to a range of metals and oxidizing chemicals. OXS3 belongs to a family of proteins that share a highly conserved domain corresponding to a putative N-acetyltransferase or thioltransferase catalytic site. Mutations within this conserved domain abolished the ability of Arabidopsis thaliana OXS3 to enhance stress tolerance in S. pombe, indicating a role in stress tolerance for the presumptive catalytic domain. A stress-sensitive mutant of AtOXS3 and enhanced tolerance of over-expression lines support the role of OXS3 in stress tolerance. The expression of tagged B. juncea and A. thaliana OXS3 proteins in plant cells revealed a subnuclear speckling pattern related to the nucleosome in discrete parts of the chromatin. It is possible that OXS3 might act as a chromatin-remodeling factor for the stress response.