Single-stranded DNA binding factor AtWHY1 modulates telomere length homeostasis in Arabidopsis.
Telomere homeostasis, a process that is essential for the maintenance of chromosome integrity, is regulated by telomerase and a collection of associated proteins. By mass spectrometry we have identified a new telomeric protein encoded by the AtWHY1 (Arabidopsis thaliana Whirly 1) gene in Arabidopsis. AtWHY1 specifically binds the single-stranded plant telomeric DNA sequences, but not double-stranded telomeric DNA. To gain insights into the function of AtWHY1 in telomere biogenesis, we have identified two Arabidopsis lines harboring T-DNA insertions in AtWHY1. These lines exhibit neither growth nor developmental defects. However, AtWHY1-deficient plants show a steady increase in the length of telomere tracts over generations. This telomere elongation is correlated with a significant increase in telomerase activity. On the contrary, transgenic plants expressing AtWHY1 show a decreased telomerase activity and shortened telomeres. The evidence presented here indicates that AtWHY1 is a new family of telomere end-binding proteins that plays a role in regulating telomere-length homeostasis in Arabidopsis.
Yoo
Hyun Hee
HH
Department of Biology and Molecular Aging Research Center, Yonsei University, Seoul 120-749, Korea.
Kwon
Chian
C
Lee
Myeong Min
MM
Chung
In Kwon
IK
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D032461:Chromosomes, Plant / Q000378:metabolism; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006706:Homeostasis / Q000502:physiology; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D030821:Plants, Genetically Modified / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000737:chemistry; D019098:Telomerase / Q000037:antagonists & inhibitors / Q000378:metabolism; D016615:Telomere / Q000378:metabolism*; D034501:Telomere-Binding Proteins / Q000378:metabolism*
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C036483:T-DNA; D034501:Telomere-Binding Proteins; C503333:Whirly1 protein, Arabidopsis; D019098:Telomerase