Document Detail


Both transcriptional and posttranscriptional mechanisms regulate human telomerase template RNA levels.
MedLine Citation:
PMID:  10330139     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The human telomerase RNA component (hTR) is present in normal somatic cells at lower levels than in cancer-derived cell lines. To understand the mechanisms regulating hTR levels in different cell types, we have compared the steady-state hTR levels in three groups of cells: (i) normal telomerase-negative human diploid cells; (ii) normal cells transfected with the human telomerase catalytic subunit, hTERT; and (iii) cells immortalized in vitro and cancer cells expressing their own endogenous hTERT. To account for the differences in steady-state hTR levels observed in these cell types, we compared the transcription rate and half-life of hTR in a subset of these cells. The half-life of hTR in telomerase-negative cells is about 5 days and is increased 1.6-fold in the presence of hTERT. The transcription rate of hTR is essentially unchanged in cells expressing exogenous hTERT, and the increased steady-state hTR level appears to be due to the increased half-life. However, the transcription rate of hTR is greatly increased in cells expressing endogenous hTERT, suggesting some overlap in transcriptional regulatory control. We conclude that the higher hTR level in cells expressing an endogenous telomerase can be a result of both increased transcription and a longer half-life and that the longer half-life might be partially a result of protection or stabilization by the telomerase catalytic subunit. The 4-week half-life of hTR in H1299 tumor cells is the longest half-life yet reported for any RNA.
Authors:
X Yi; V M Tesmer; I Savre-Train; J W Shay; W E Wright
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Molecular and cellular biology     Volume:  19     ISSN:  0270-7306     ISO Abbreviation:  Mol. Cell. Biol.     Publication Date:  1999 Jun 
Date Detail:
Created Date:  1999-06-17     Completed Date:  1999-06-17     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  8109087     Medline TA:  Mol Cell Biol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  3989-97     Citation Subset:  IM    
Affiliation:
Department of Cell Biology and Neuroscience, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75235-9039, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blotting, Northern
Cell Nucleus / metabolism
Cell Transformation, Neoplastic
Chromatography, Agarose
DNA-Binding Proteins
Epithelial Cells / metabolism
Fibroblasts / metabolism
Half-Life
Humans
Lung / metabolism
Mice
Models, Genetic
RNA / physiology*
RNA Processing, Post-Transcriptional / physiology*
RNA, Messenger / metabolism
RNA, Untranslated*
Retroviridae / genetics
Reverse Transcriptase Polymerase Chain Reaction
Ribonucleases / metabolism
Telomerase / genetics*,  physiology*
Templates, Genetic
Time Factors
Transcription, Genetic*
Transfection
Tumor Cells, Cultured
Grant Support
ID/Acronym/Agency:
AG07992/AG/NIA NIH HHS
Chemical
Reg. No./Substance:
0/DNA-Binding Proteins; 0/RNA, Messenger; 0/RNA, Untranslated; 0/hTR RNA; 0/telomerase RNA; 63231-63-0/RNA; EC 2.7.7.49/Telomerase; EC 3.1.-/Ribonucleases
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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