The WD40 Domain Protein MSI1 Functions in a Histone Deacetylase Complex to Fine-Tune Abscisic Acid Signaling
2016 (English)In: The Plant Cell, ISSN 1040-4651, E-ISSN 1532-298X, Vol. 28, no 1, 42-54 p.Article in journal (Refereed) Published
MSI1 belongs to a family of histone binding WD40-repeat proteins. Arabidopsis thaliana contains five genes encoding MSI1-like proteins, but their functions in diverse chromatin-associated complexes are poorly understood. Here, we show that MSI1 is part of a histone deacetylase complex. We copurified HISTONE DEACETYLASE19 (HDA19) with MSI1 and transcriptional regulatory SIN3-like proteins and provide evidence that MSI1 and HDA19 associate into the same complex in vivo. These data suggest that MSI1, HDA19, and HISTONE DEACETYLATION COMPLEX1 protein form a core complex that can integrate various SIN3-like proteins. We found that reduction of MSI1 or HDA19 causes upregulation of abscisic acid (ABA) receptor genes and hypersensitivity of ABA-responsive genes. The MSI1-HDA19 complex fine-tunes ABA signaling by binding to the chromatin of ABA receptor genes and by maintaining low levels of acetylation of histone H3 at lysine 9, thereby affecting the expression levels of ABA receptor genes. Reduced MSI1 or HDA19 levels led to increased tolerance to salt stress corresponding to the increased ABA sensitivity of gene expression. Together, our results reveal the presence of an MSI1-HDA19 complex that fine-tunes ABA signaling in Arabidopsis.
Place, publisher, year, edition, pages
2016. Vol. 28, no 1, 42-54 p.
Botany Biochemistry and Molecular Biology Cell Biology
IdentifiersURN: urn:nbn:se:uu:diva-279517DOI: 10.1105/tpc.15.00763ISI: 000369814300008PubMedID: 26704384OAI: oai:DiVA.org:uu-279517DiVA: diva2:908286
FunderSwedish Research Council, 2011-5010Swedish Research Council, 621-2011-4423Science for Life Laboratory - a national resource center for high-throughput molecular bioscienceKnut and Alice Wallenberg Foundation