Protection of Telomeres 1 is required for telomere integrity in the moss Physcomitrella patens

Authors

Eugene V. Shakirov, Marshall UniversityFollow
Pierre-François Perroud
Andrew D. Nelson
Maren E. Cannell
Ralph S. Quatrano
Dorothy E. Shippen

Document Type

Article

Publication Date

6-2010

Abstract

In vertebrates, the single-stranded telomeric DNA binding protein Protection of Telomeres 1 (POT1) shields chromosome ends and prevents them from eliciting a DNA damage response. By contrast, Arabidopsis thaliana encodes two divergent full-length POT1 paralogs that do not exhibit telomeric DNA binding in vitro and have evolved to mediate telomerase regulation instead of chromosome end protection. To further investigate the role of POT1 in plants, we established the moss Physcomitrella patens as a new model for telomere biology and a counterpoint to Arabidopsis. The sequence and architecture of the telomere tract is similar in P. patens and Arabidopsis, but P. patens harbors only a single-copy POT1 gene. Unlike At POT1 proteins, Pp POT1 efficiently bound single-stranded telomeric DNA in vitro. Deletion of the P. patens POT1 gene resulted in the rapid onset of severe developmental defects and sterility. Although telomerase activity levels were unperturbed, telomeres were substantially shortened, harbored extended G-overhangs, and engaged in end-to-end fusions. We conclude that the telomere capping function of POT1 is conserved in early diverging land plants but is subsequently lost in Arabidopsis.

Comments

Copyright © American Society of Plant Biologists.

Recommended Citation

Shakirov, E.V., Perroud, P.F., Nelson, A.D., Cannell, M.E., Quatrano, R.S. and Shippen, D.E., 2010. Protection of Telomeres 1 is required for telomere integrity in the moss Physcomitrella patens. The Plant Cell, 22(6), pp.1838-1848.