title: Telomere-binding protein regulates the chromosome ends through the interaction with histone deacetylases in Arabidopsis thaliana.
abstract: Telomeres are nucleoprotein complexes at the end of eukaryotic chromosomes. Many telomere-binding proteins bind to telomeric repeat sequences and further generate T-loops in animals. However, it is not clear if they regulate telomere organization using epigenetic mechanisms and how the epigenetic molecules are involved in regulating the telomeres. Here, we show direct interactions between the telomere-binding protein, AtTRB2 and histone deacetylases, HDT4 and HDA6, in vitro and in vivo AtTRB2 mediates the associations of HDT4 and HDA6 with telomeric repeats. Telomere elongation is found in AtTRB2, HDT4 and HDA6 mutants over generations, but also in met1 and cmt3 DNA methyltransferases mutants. We also characterized HDT4 as an Arabidopsis H3K27 histone deacetylase. HDT4 binds to acetylated peptides at residue K27 of histone H3 in vitro, and deacetylates this residue in vivo Our results suggest that AtTRB2 also has a role in the regulation of telomeric chromatin as a possible scaffold protein for recruiting the epigenetic regulators in Arabidopsis, in addition to its telomere binding and length regulation activity. Our data provide evidences that epigenetic molecules associate with telomeres by direct physical interaction with telomere-binding proteins and further regulate homeostasis of telomeres in Arabidopsis thaliana.
authors: Department of Systems Biology, Yonsei University, Seoul 03722, Republic of Korea.
authors: Won Kyung
authors: WK
authors: Lee
authors: Department of Systems Biology, Yonsei University, Seoul 03722, Republic of Korea mhcho@yonsei.ac.kr.
authors: Myeon Haeng
authors: MH
authors: Cho
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D032461:Chromosomes, Plant; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism; D009154:Mutation; D030821:Plants, Genetically Modified; D016615:Telomere / Q000235:genetics / Q000378:metabolism; D059505:Telomere Homeostasis / Q000235:genetics; D034501:Telomere-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D006655:Histone Deacetylases; D008239:Lysine; D034501:Telomere-Binding Proteins; C529793:At5g67580 protein, Arabidopsis; C432452:AT5G63110 protein, Arabidopsis; C000619240:HDT4 protein, Arabidopsis