Characterization of interactions between PinX1 and human telomerase subunits hTERT and hTR.

Journal Article (Journal Article)

The addition of telomeric repeats to chromosome ends by the enzyme telomerase is a highly orchestrated process. Although much is known regarding telomerase catalytic activity in vitro, less is known about how this activity is regulated in vivo to ensure proper telomere elongation. One protein that appears to be involved in negatively regulating telomerase function in vivo is PinX1 because overexpression of PinX1 inhibits telomerase activity and causes telomere shortening. To understand the nature of this repression, we characterized the interactions among PinX1 and the core components of telomerase, the human telomerase reverse transcriptase (hTERT) and associated human telomerase RNA (hTR). We now show that in vitro PinX1 binds directly to the hTERT protein subunit, primarily to the hTR-binding domain, as well as to the hTR subunit. However, in a cellular context, the association of PinX1 with hTR is dependent on the presence of hTERT. Taken together, we suggest that PinX1 represses telomerase activity in vivo by binding to the assembled hTERT.hTR complex.

Full Text

Duke Authors

Cited Authors

  • Banik, SSR; Counter, CM

Published Date

  • December 10, 2004

Published In

Volume / Issue

  • 279 / 50

Start / End Page

  • 51745 - 51748

PubMed ID

  • 15381700

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M408131200


  • eng

Conference Location

  • United States