Stable maintenance of telomeres is critical to preserve genomic integrity and prevent accumulation of undesired mutations that might lead to various human diseases. In mammalian cells, GT-rich telomeric repeats are bound by the six-protein """"""""shelterin"""""""" complex (composed of TRF1, TRF2, RAP1, TIN2, TPP1 and POT1) and extended by the specialized reverse transcriptase known as telomerase. The shelterin complex is essential to prevent DNA repair proteins from fusing telomeres and DNA damage checkpoint proteins from causing permanent cell cycle arrest. On the other hand, these DNA damage response factors must gain at least transient access to telomeres, since they play critical roles in both telomere protection and telomerase recruitment. Thus, the proper maintenance of telomeres involves dynamic changes between """"""""closed"""""""" (protected) and """"""""open"""""""" (accessible) states. However, it is still not fully understood how individual subunits of the shelterin complex are regulated to ensure proper transition of the telomere status. In addition, the critical telomere target(s) for DNA damage checkpoint proteins remain to be established. Therefore, we propose to utilize fission yeast Schizosaccharomyces pombe as a model system to investigate how telomere maintenance is ensured by collaboration among telomere specific factors and DNA damage response factors. Fission yeast should serve as an attractive model system for mammalian telomere maintenance mechanism, since the shelterin complex, telomerase components, and DNA damage response proteins are highly conserved between fission yeast and mammals.

Public Health Relevance

Stable maintenance of telomeres is critical to preserve genomic integrity and prevent accumulation of undesired mutations that might lead to tumor formation. The overall goals of this proposal are to provide a detailed knowledge of the mechanisms that allow the telomere protection complex shelterin and DNA damage checkpoint sensor kinases Rad3 (ATR) and Tel1 (ATM) to work in concert to achieve stable telomere maintenance in fission yeast Schizosaccharomyces pombe. Since proteins involved in telomere maintenance and DNA damage responses are highly conserved between fission yeast and humans, we expect our findings to have major impacts in guiding future studies of human telomere regulations.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM078253-07
Application #
8306902
Study Section
Molecular Genetics C Study Section (MGC)
Program Officer
Carter, Anthony D
Project Start
2006-08-01
Project End
2015-07-31
Budget Start
2012-08-01
Budget End
2013-07-31
Support Year
7
Fiscal Year
2012
Total Cost
$321,647
Indirect Cost
$116,647
Name
University of Illinois at Chicago
Department
Biochemistry
Type
Schools of Medicine
DUNS #
098987217
City
Chicago
State
IL
Country
United States
Zip Code
60612
Matmati, Samah; Vaurs, Mélina; Escandell, José M et al. (2018) The fission yeast Stn1-Ten1 complex limits telomerase activity via its SUMO-interacting motif and promotes telomeres replication. Sci Adv 4:eaar2740
Mennie, Amanda K; Moser, Bettina A; Nakamura, Toru M (2018) LARP7-like protein Pof8 regulates telomerase assembly and poly(A)+TERRA expression in fission yeast. Nat Commun 9:586
Nie, Minghua; Moser, Bettina A; Nakamura, Toru M et al. (2017) SUMO-targeted ubiquitin ligase activity can either suppress or promote genome instability, depending on the nature of the DNA lesion. PLoS Genet 13:e1006776
Gadaleta, Mariana C; Das, Mukund M; Tanizawa, Hideki et al. (2016) Swi1Timeless Prevents Repeat Instability at Fission Yeast Telomeres. PLoS Genet 12:e1005943
Moser, Bettina A; Raguimova, Olga N; Nakamura, Toru M (2015) Ccq1-Tpz1TPP1 interaction facilitates telomerase and SHREC association with telomeres in fission yeast. Mol Biol Cell 26:3857-66
Audry, Julien; Maestroni, Laetitia; Delagoutte, Emmanuelle et al. (2015) RPA prevents G-rich structure formation at lagging-strand telomeres to allow maintenance of chromosome ends. EMBO J 34:1942-58
Miyagawa, Keisuke; Low, Ross S; Santosa, Venny et al. (2014) SUMOylation regulates telomere length by targeting the shelterin subunit Tpz1(Tpp1) to modulate shelterin-Stn1 interaction in fission yeast. Proc Natl Acad Sci U S A 111:5950-5
Harland, Jennifer L; Chang, Ya-Ting; Moser, Bettina A et al. (2014) Tpz1-Ccq1 and Tpz1-Poz1 interactions within fission yeast shelterin modulate Ccq1 Thr93 phosphorylation and telomerase recruitment. PLoS Genet 10:e1004708
Moser, Bettina A; Chang, Ya-Ting; Nakamura, Toru M (2014) Telomere regulation during the cell cycle in fission yeast. Methods Mol Biol 1170:411-24
Chang, Ya-Ting; Moser, Bettina A; Nakamura, Toru M (2013) Fission yeast shelterin regulates DNA polymerases and Rad3(ATR) kinase to limit telomere extension. PLoS Genet 9:e1003936

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