Telomerase is the ribonucleoprotein complex responsible for replicating the G-rich strand of telomeres, the physical ends of chromosomes. In humans, it is composed of a 451 nt RNA (hTR) that includes an RNA template, and associated proteins, including a unique reverse transcriptase (hTERT). In this grant application, we propose structural, thermodynamic, and functional studies of conserved domains of hTR and protein-RNA interactions that have been proposed to be important for telomerase activity, accumulation, and localization, and investigate the effect of telomerase RNA mutations linked to disease. Primarily NMR, as well as some X-ray crystallography, will be used for structural studies.
The specific aims are: (1) Determine the structure of the highly conserved p2b-p3 pseudoknot sequence and the functional importance of the conserved nucleotides; 2) Determine the structure of the pseudoknot (core) domain of hTR by a combination of structural studies and modeling; (3) Investigate the possible interaction of the RT domain of hTERT with the pseudoknot; (4) Investigate the CR7 hairpin loop to determine the sequence and structural elements involved in Cajal body localization and in accumulation of hTR; (5) Determine the structure of the telomeras 3. H/ACA domain and investigate its interactions with the human H/ACA snoRNP proteins NopIO, Nh2, Gar1, and dyskerin. In spite of the high level of interest in telomerase and its biological and medical importance, almost no three-dimensional structural studies have been reported to date. No structures of telomerase proteins have been determined, either alone or in complex with the TR. The overall objective of this work is to provide a structural basis for understanding some of the RNA and RNA-protein interactions that occur in the functional telomerase ribonucleoprotein complex. The results of these investigations will provide a molecular basis for understanding telomerase function as well as mutations linked to disease, and provide a rational basis for design of drugs to affect telomerase activity in vivo.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM048123-14
Application #
7124335
Study Section
Molecular and Cellular Biophysics Study Section (BBCA)
Program Officer
Lewis, Catherine D
Project Start
1992-08-01
Project End
2009-08-31
Budget Start
2006-09-01
Budget End
2007-08-31
Support Year
14
Fiscal Year
2006
Total Cost
$306,814
Indirect Cost
Name
University of California Los Angeles
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Jiang, Jiansen; Wang, Yaqiang; SuĊĦac, Lukas et al. (2018) Structure of Telomerase with Telomeric DNA. Cell 173:1179-1190.e13
Upton, Heather E; Chan, Henry; Feigon, Juli et al. (2017) Shared Subunits of Tetrahymena Telomerase Holoenzyme and Replication Protein A Have Different Functions in Different Cellular Complexes. J Biol Chem 292:217-228
Chan, Henry; Wang, Yaqiang; Feigon, Juli (2017) Progress in Human and Tetrahymena Telomerase Structure Determination. Annu Rev Biophys 46:199-225
Wang, Yaqiang; Feigon, Juli (2017) Structural biology of telomerase and its interaction at telomeres. Curr Opin Struct Biol 47:77-87
Cash, Darian D; Feigon, Juli (2017) Structure and folding of the Tetrahymena telomerase RNA pseudoknot. Nucleic Acids Res 45:482-495
Wang, Yaqiang; Yesselman, Joseph D; Zhang, Qi et al. (2016) Structural conservation in the template/pseudoknot domain of vertebrate telomerase RNA from teleost fish to human. Proc Natl Acad Sci U S A 113:E5125-34
Feigon, Juli; Chan, Henry; Jiang, Jiansen (2016) Integrative structural biology of Tetrahymena telomerase - insights into catalytic mechanism and interaction at telomeres. FEBS J 283:2044-50
Jiang, Jiansen; Chan, Henry; Cash, Darian D et al. (2015) Structure of Tetrahymena telomerase reveals previously unknown subunits, functions, and interactions. Science 350:aab4070
Singh, Mahavir; Wang, Zhonghua; Cascio, Duilio et al. (2015) Structure and interactions of the CS domain of human H/ACA RNP assembly protein Shq1. J Mol Biol 427:807-23
Kim, Nak-Kyoon; Zhang, Qi; Feigon, Juli (2014) Structure and sequence elements of the CR4/5 domain of medaka telomerase RNA important for telomerase function. Nucleic Acids Res 42:3395-408

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