Related Experiment Videos
Vaults and telomerase share a common subunit, TEP1.
V A Kickhoefer1, A G Stephen, L Harrington
1Department of Biological Chemistry, UCLA School of Medicine and Jonsson Comprehensive Cancer Center, Los Angeles, California 90095, USA. vkick@mednet.ucla.edu
The Journal of Biological Chemistry
|November 7, 1999
Summary
Mammalian vaults, large RNP complexes, contain TEP1, also known as the telomerase-associated protein 1. Despite TEP1
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Vaults are large, enigmatic cytoplasmic ribonucleoprotein complexes.
- Mammalian vaults are composed of high molecular mass proteins, including a 240-kDa component.
- The function of vaults remains largely undetermined.
Purpose of the Study:
- To identify the 240-kDa vault protein.
- To investigate the relationship between vaults and telomerase.
- To elucidate the role of TEP1 in vault structure and function.
Main Methods:
- Partial cDNA sequencing to identify the 240-kDa vault protein.
- Yeast three-hybrid assays to study RNA-protein interactions.
- Biochemical assays to assess telomerase activity in vaults.
Main Results:
- The 240-kDa vault protein was identified as TEP1 (telomerase-associated protein 1), the mammalian homolog of Tetrahymena p80.
- TEP1 interacts with mammalian telomerase RNA and hTERT.
- Vault particles contain TEP1 but exhibit no detectable telomerase activity.
- Human vault RNAs (vRNAs) interact sequence-specifically with TEP1.
- TEP1 possesses 16 WD40 repeats, suggesting a structural role in the eight-fold symmetric vault particle.
Conclusions:
- TEP1 is a shared component of both vaults and telomerase.
- Vaults do not possess telomerase activity, despite containing TEP1.
- TEP1 may play a conserved role in ribonucleoprotein complex assembly, structure, or function.