Premium
Human Telomerase Reverse Transcriptase (hTERT) Positively Regulates 26S Proteasome Activity
Author(s) -
Im Eunju,
Yoon Jong Bok,
Lee HanWoong,
Chung Kwang Chul
Publication year - 2017
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.25607
Subject(s) - telomerase reverse transcriptase , telomerase , telomere , protein subunit , proteasome , reverse transcriptase , ubiquitin , microbiology and biotechnology , chemistry , biology , cancer research , rna , dna , biochemistry , gene
Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of telomerase, an RNA‐dependent DNA polymerase that elongates telomeric DNA. hTERT displays several extra‐telomeric functions that are independent of its telomere‐regulatory function, including tumor progression, and neuronal cell death regulation. In this study, we evaluated these additional hTERT non‐telomeric functions. We determined that hTERT interacts with several 19S and 20S proteasome subunits. The 19S regulatory particle and 20S core particle are part of 26S proteasome complex, which plays a central role in ubiquitin‐dependent proteolysis. In addition, hTERT positively regulated 26S proteasome activity independent of its enzymatic activity. Moreover, hTERT enhanced subunit interactions, which may underlie hTERT's ability of hTERT to stimulate the 26S proteasome. Furthermore, hTERT displayed cytoprotective effect against ER stress via the activation of 26S proteasome in acute myeloid leukemia cells. Our data suggest that hTERT acts as a novel chaperone to promote 26S proteasome assembly and maintenance. J. Cell. Physiol. 232: 2083–2093, 2017. © 2016 Wiley Periodicals, Inc.