Document Detail


Recombination-based telomere maintenance is dependent on Tel1-MRN and Rap1 and inhibited by telomerase, Taz1, and Ku in fission yeast.
MedLine Citation:
PMID:  18160711     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Fission yeast cells survive loss of the telomerase catalytic subunit Trt1 (TERT) through recombination-based telomere maintenance or through chromosome circularization. Although trt1Delta survivors with linear chromosomes can be obtained, they often spontaneously circularize their chromosomes. Therefore, it was difficult to establish genetic requirements for telomerase-independent telomere maintenance. In contrast, when the telomere-binding protein Taz1 is also deleted, taz1Delta trt1Delta cells are able to stably maintain telomeres. Thus, taz1Delta trt1Delta cells can serve as a valuable tool in understanding the regulation of telomerase-independent telomere maintenance. In this study, we show that the checkpoint kinase Tel1 (ATM) and the DNA repair complex Rad32-Rad50-Nbs1 (MRN) are required for telomere maintenance in taz1Delta trt1Delta cells. Surprisingly, Rap1 is also essential for telomere maintenance in taz1Delta trt1Delta cells, even though recruitment of Rap1 to telomeres depends on Taz1. Expression of catalytically inactive Trt1 can efficiently inhibit recombination-based telomere maintenance, but the inhibition requires both Est1 and Ku70. While Est1 is essential for recruitment of Trt1 to telomeres, Ku70 is dispensable. Thus, we conclude that Taz1, TERT-Est1, and Ku70-Ku80 prevent telomere recombination, whereas MRN-Tel1 and Rap1 promote recombination-based telomere maintenance. Evolutionarily conserved proteins in higher eukaryotic cells might similarly contribute to telomere recombination.
Authors:
Lakxmi Subramanian; Bettina A Moser; Toru M Nakamura
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2007-12-26
Journal Detail:
Title:  Molecular and cellular biology     Volume:  28     ISSN:  1098-5549     ISO Abbreviation:  Mol. Cell. Biol.     Publication Date:  2008 Mar 
Date Detail:
Created Date:  2008-02-15     Completed Date:  2008-03-17     Revised Date:  2011-09-26    
Medline Journal Info:
Nlm Unique ID:  8109087     Medline TA:  Mol Cell Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1443-55     Citation Subset:  IM    
Affiliation:
Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, 900 S. Ashland Ave., MC669, Chicago, IL 60607, USA. nakamut@uic.edu
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MeSH Terms
Descriptor/Qualifier:
Antigens, Nuclear / genetics
DNA-Binding Proteins / antagonists & inhibitors*,  genetics
Plasmids
Protein-Serine-Threonine Kinases / genetics,  metabolism*
Recombination, Genetic
Schizosaccharomyces / genetics,  physiology*
Schizosaccharomyces pombe Proteins / antagonists & inhibitors*,  genetics,  metabolism*
Telomerase / antagonists & inhibitors*,  genetics
Telomere / genetics,  physiology*
Telomere-Binding Proteins / antagonists & inhibitors*,  genetics,  metabolism*
Grant Support
ID/Acronym/Agency:
GM078253/GM/NIGMS NIH HHS; GM28039/GM/NIGMS NIH HHS; R01 GM078253-02/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Antigens, Nuclear; 0/DNA-Binding Proteins; 0/Ku autoantigen; 0/Rap1 protein, S pombe; 0/Schizosaccharomyces pombe Proteins; 0/Telomere-Binding Proteins; 0/taz1 protein, S pombe; EC 2.7.1.37/tel1 protein, S pombe; EC 2.7.11.1/Protein-Serine-Threonine Kinases; EC 2.7.7.49/Telomerase
Comments/Corrections

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