Letter abstract


Nature Cell Biology 6, 673 - 680 (2004)
Published online: 6 June 2004 | doi:10.1038/ncb1142

PTOP interacts with POT1 and regulates its localization to telomeres

Dan Liu1, Amin Safari1, Matthew S O'Connor1, Doug W. Chan1, Andrew Laegeler1, Jun Qin1 & Zhou Songyang1

Top

Telomere maintenance has been implicated in cancer and ageing, and requires cooperation between a multitude of telomeric factors, including telomerase, TRF1, TRF2, RAP1, TIN2, Tankyrase, PINX1 and POT1 (refs 1–12). POT1 belongs to a family of oligonucleotide-binding (OB)-fold-containing proteins that include Oxytricha nova TEBP, Cdc13, and spPot1, which specifically recognize telomeric single-stranded DNA (ssDNA)10, 13, 14, 15, 16, 17, 18, 19. In human cells, the loading of POT1 to telomeric ssDNA controls telomerase-mediated telomere elongation12. Surprisingly, a human POT1 mutant lacking an OB fold is still recruited to telomeres. However, the exact mechanism by which this recruitment occurs remains unclear. Here we identify a novel telomere protein, PTOP, which interacts with both POT1 and TIN2. PTOP binds to the carboxyl terminus of POT1 and recruits it to telomeres. Inhibition of PTOP by RNA interference (RNAi) or disruption of the PTOP–POT1 interaction hindered the localization of POT1 to telomeres. Furthermore, expression of the respective interaction domains on PTOP and POT1 alone extended telomere length in human cells. Therefore, PTOP heterodimerizes with POT1 and regulates POT1 telomeric recruitment and telomere length.

Top
  1. Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA.

Correspondence to: Zhou Songyang1 e-mail: songyang@bcm.tmc.edu



MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.

NEWS AND VIEWS

Research Highlights

Nature Structural & Molecular Biology News and Views (01 Jul 2004)

A common means to an end

Nature Structural & Molecular Biology News and Views (01 Mar 2007)


Extra navigation

Subscribe to Nature Cell Biology

Subscribe

Open Innovation Challenges