In dyskeratosis congenita (DC) and many other disease states, patient health and longevity are limited by insufficient hematopoietic renewal. Because bone marrow transplantation has not been an effective DC therapy, new strategies must be devised. This application tests the hypothesis that X-linked DC derives from a specific telomerase RNA deficiency and investigates telomerase function in lymphoid cells, with the long-term goal of understanding disease molecular mechanism(s) and developing effective disease therapies.
AIM I : Telomerase function will be restored in X-linked DC patient fibroblasts expressing altered dyskerin, in parallel with telomerase activation in family-matched X-linked DC carrier fibroblasts expressing wild-type dyskerin. DC patient cells rescued for telomerase function will be tested for the acquisition of normal proliferative capacity and telomere length maintenance. These findings will be relevant for understanding disease mechanism and also may provide proof-of-principle for telomerase activation as a clinical therapy.
AIM II :
Aim I telomerase-activated cell lines expressing DC or normal dyskerin will be used to investigate potential DC dyskerin defects in the biogenesis of RNAs other than telomerase. Unlike currently available DC patient cell cultures, cell lines +TERT have robust, uniform growth and will therefore avoid misleading characterization of RNA biogenesis defects secondary to changes in proliferation rate or the percentage of cells undergoing active proliferation. Dyskerin-associated RNA accumulation and dyskerin enzyme function in ribosomal RNA precursor modification and cleavage will be assayed.
AIM III : Mechanisms of telomerase function in normal lymphoid cells will be studied using a cell culture system that resolves telomere length -dependent and -independent roles for telomerase in promoting cell growth and survival. A potential third role for telomerase in protection against cell death will also be evaluated. These studies will reveal new roles for telomerase in the cells that are most significantly affected in DC.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL079585-02
Application #
6951142
Study Section
Special Emphasis Panel (ZHL1-CSR-D (S1))
Program Officer
Qasba, Pankaj
Project Start
2004-09-30
Project End
2007-07-31
Budget Start
2005-08-01
Budget End
2006-07-31
Support Year
2
Fiscal Year
2005
Total Cost
$228,000
Indirect Cost
Name
University of California Berkeley
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Wu, Robert Alexander; Tam, Jane; Collins, Kathleen (2017) DNA-binding determinants and cellular thresholds for human telomerase repeat addition processivity. EMBO J 36:1908-1927
Chiba, Kunitoshi; Vogan, Jacob M; Wu, Robert A et al. (2017) Endogenous Telomerase Reverse Transcriptase N-Terminal Tagging Affects Human Telomerase Function at Telomeres In Vivo. Mol Cell Biol 37:
Wu, R Alex; Upton, Heather E; Vogan, Jacob M et al. (2017) Telomerase Mechanism of Telomere Synthesis. Annu Rev Biochem 86:439-460
Vogan, Jacob M; Zhang, Xiaozhu; Youmans, Daniel T et al. (2016) Minimized human telomerase maintains telomeres and resolves endogenous roles of H/ACA proteins, TCAB1, and Cajal bodies. Elife 5:
Wu, Robert Alexander; Dagdas, Yavuz S; Yilmaz, S Tunc et al. (2015) Single-molecule imaging of telomerase reverse transcriptase in human telomerase holoenzyme and minimal RNP complexes. Elife 4:
Hockemeyer, Dirk; Collins, Kathleen (2015) Control of telomerase action at human telomeres. Nat Struct Mol Biol 22:848-52
Vogan, Jacob M; Collins, Kathleen (2015) Dynamics of Human Telomerase Holoenzyme Assembly and Subunit Exchange across the Cell Cycle. J Biol Chem 290:21320-35
Katibah, George E; Qin, Yidan; Sidote, David J et al. (2014) Broad and adaptable RNA structure recognition by the human interferon-induced tetratricopeptide repeat protein IFIT5. Proc Natl Acad Sci U S A 111:12025-30
Wu, Robert Alexander; Collins, Kathleen (2014) Sequence specificity of human telomerase. Proc Natl Acad Sci U S A 111:11234-5
Sexton, Alec N; Regalado, Samuel G; Lai, Christine S et al. (2014) Genetic and molecular identification of three human TPP1 functions in telomerase action: recruitment, activation, and homeostasis set point regulation. Genes Dev 28:1885-99

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