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Updated: Jun 20, 2026
08:35
Inducible and Reversible Dominant-negative (DN) Protein Inhibition
Published on: January 7, 2019
Mechanism of dominant-negative telomerase function.
Binh N Nguyen1, Lynne W Elmore, Shawn E Holt
1Department of Pathology, Medical College of Virginia at Virginia Commonwealth University, Richmond, VA, USA.
Cell Cycle (Georgetown, Tex.)
|September 10, 2009
Summary
Dominant-negative hTERT (DN-hTERT) causes tumor cell death by targeting wild-type hTERT for degradation. This study reveals DN-hTERT complexes with wild-type hTERT, leading to cytoplasmic export and degradation, offering new therapeutic targets.
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- Human telomerase, composed of hTR and hTERT, maintains telomeres.
- Dominant-negative hTERT (DN-hTERT) induces telomere shortening and cell death in tumor cells.
- The precise mechanism and cellular fate of DN-hTERT remain unclear.
Purpose of the Study:
- To elucidate the mechanism of dominant-negative hTERT function.
- To investigate the cellular fate of DN-hTERT and its effect on wild-type hTERT.
- To explore novel therapeutic strategies targeting telomerase degradation.
Main Methods:
- Fusion of wild-type and dominant-negative hTERT with GFP.
- Expression of tagged and untagged constructs in telomerase-positive cells.
- Analysis of protein localization, ubiquitination, and degradation pathways.
Main Results:
- GFP-DN-hTERT expression led to cytoplasmic export and ubiquitination-mediated degradation.
- Co-expression with wild-type hTERT resulted in decreased wild-type hTERT levels, cytoplasmic export, and increased ubiquitination.
- Evidence suggests DN-hTERT forms a complex with wild-type hTERT, inducing its degradation.
Conclusions:
- DN-hTERT induces degradation of wild-type hTERT through cytoplasmic export and ubiquitination.
- Proposed mechanisms involve heterodimer formation and accelerated degradation.
- Understanding telomerase degradation pathways can inform drug design for cancer therapy.
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