Arabidopsis thaliana telomeric DNA-binding protein 1 is required for telomere length homeostasis and its Myb-extension domain stabilizes plant telomeric DNA binding.
Telomeres are specific protein-DNA complexes that protect the ends of eukaryotic chromosomes from fusion and degradation and are maintained by a specialized mechanism exerted by telomerase and telomere-binding proteins (TBPs), which are evolutionarily conserved. AtTBP1 is an Arabidopsis thaliana protein that binds plant telomeric DNA in vitro. Here, we demonstrated that lack of AtTBP1 results in a deregulation of telomere length control, with mutant telomeres expanding steadily by the fourth generation. DNA-binding studies with mutant AtTBP1 proteins showed that the Myb-extension domain of AtTBP1 is required for binding to plant telomeric DNA. Our results suggest that AtTBP1 is involved in the telomere length mechanism in A. thaliana and that the Myb-extension domain of AtTBP1 may stabilize plant telomeric DNA binding.
Hwang
Moo Gak
MG
Department of Biology, Yonsei University, Seoul 120-749, Republic of Korea.
Cho
Myeon Haeng
MH
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D018744:DNA, Plant / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D006706:Homeostasis; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D020598:Proto-Oncogene Proteins c-myb / Q000737:chemistry; D016615:Telomere / Q000737:chemistry / Q000378:metabolism*
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; D020598:Proto-Oncogene Proteins c-myb; C434737:TBP1 protein, Arabidopsis