Previous Article | Next Article ![]()
Molecular and Cellular Biology, September 2001, p. 6151-6160, Vol. 21, No. 18
Ontario Cancer Institute/Amgen Institute,
Department of Medical Biophysics, University of Toronto, Toronto,
Ontario, Canada,1 and Amgen, Inc.,
Thousand Oaks, California2
Received 22 March 2001/Returned for modification 30 April
2001/Accepted 2 July 2001
The telomerase enzyme exists as a large complex (~1,000 kDa) in
mammals and at minimum is composed of the telomerase RNA and the
catalytic subunit telomerase reverse transcriptase
(TERT). In Saccharomyces cerevisiae, telomerase appears to
function as an interdependent dimer or multimer in vivo (J. Prescott
and E. H. Blackburn, Genes Dev. 11:2790-2800, 1997). However, the
requirements for multimerization are not known, and it remained unclear
whether telomerase exists as a multimer in other organisms. We show
here that human TERT (hTERT) forms a functional multimer in a rabbit reticulocyte lysate reconstitution assay and in human cell extracts. Two separate, catalytically inactive TERT proteins can complement each
other in trans to reconstitute catalytic activity. This
complementation requires the amino terminus of one hTERT and the
reverse transcriptase and C-terminal domains of the second hTERT. The
telomerase RNA must associate with only the latter hTERT for
reconstitution of telomerase activity to occur. Multimerization of
telomerase also facilitates the recognition and elongation of
substrates in vitro and in vivo. These data suggest that the catalytic
core of human telomerase may exist as a functionally cooperative dimer
or multimer in vivo.
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.18.6151-6160.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Functional Multimerization of the Human Telomerase
Reverse Transcriptase
*
Corresponding author. Mailing address for Tara L. Beattie: Department of Biochemistry and Molecular Biology, University
of Calgary, Calgary, Alberta, Canada T2N 4N1. Phone: (403) 220-8328. Fax: (403) 283-8727. E-mail: tbeattie{at}ucalgary.ca. Mailing
address for Lea Harrington: Ontario Cancer Institute/Amgen Institute, Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada M5G 2C1. Phone: (416) 204-2231. Fax: (416)
204-2277. E-mail: leah{at}uhnres.utoronto.ca.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|