An Arabidopsis splicing RNP variant STEP1 regulates telomere length homeostasis by restricting access of nuclease and telomerase.
Telomere is an essential DNA-protein complex composed of repetitive DNA and binding proteins to protect the chromosomal ends in eukaryotes. Telomere length is regulated by a specialized RNA-dependent DNA polymerase, telomerase and associated proteins. We show here a potential role of STEP1 that was previously isolated by affinity chromatography in controlling telomere length. While STEP1 requires both RNA-binding domains for telomere binding and subsequent DNA protection, it requires only one RBD to interact with telomerase. The differential telomerase inhibitory activity depending on STEP1 concentrations may suggest that STEP1 contributes to controlling telomere length homeostasis, likely by limiting the accessibility of nuclease or telomerase to telomeric DNA.
Yoo
Hyun Hee
HH
Department of Biology, WCU Program, Yonsei University, Seoul, 120-740, Korea.
Kwon
Chian
C
Chung
In Kwon
IK
D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000378:metabolism*; D060365:Chloroplast Proteins; D003851:Deoxyribonucleases / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D011485:Protein Binding; D020033:Protein Isoforms / Q000378:metabolism*; D019154:Protein Splicing; D017434:Protein Structure, Tertiary / Q000502:physiology; D012261:Ribonucleoproteins / Q000378:metabolism*; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000378:metabolism*
D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; D012261:Ribonucleoproteins; D019098:Telomerase; D003851:Deoxyribonucleases