Hyper-phosphorylated retinoblastoma protein suppresses telomere elongation

Biosci Biotechnol Biochem. 2008 Feb;72(2):630-5. doi: 10.1271/bbb.70715. Epub 2008 Feb 7.

Abstract

Immortalized cell lines maintain telomeres by the expression of telomerase or by a mechanism designated alternative lengthening of telomeres (ALT). Although DNA polymerase alpha (pol-alpha) is reported to be required for telomere maintenance, the critical role of pol-alpha in telomere maintenance has not been firmly determined. We examined the role of retinoblastoma protein (pRb) and pol-alpha in the regulation of telomere length, using telomere-fiber FISH. Telomere length varied dependent on the intracellular abundance of pol-alpha or pRb in HeLa cells. A proportion of hyper-phosphorylated pRb (ppRb) molecules localized to sites of telomeric DNA replication in HeLa cells. Pol-alpha might thus contribute to telomere maintenance, and might be regulated by ppRb.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • HeLa Cells
  • Humans
  • In Situ Hybridization, Fluorescence
  • Phosphorylation
  • Retinoblastoma Protein / metabolism*
  • Telomere*

Substances

  • Retinoblastoma Protein