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Updated: Jul 7, 2026

Inducible and Reversible Dominant-negative (DN) Protein Inhibition
Published on: January 7, 2019
Hyper-phosphorylated retinoblastoma protein suppresses telomere elongation
Masaharu Takemura1, Kazuto Sugimura, Katsuzumi Okumura
1Department of Biology, Faculty of Science, Tokyo University of Science (RIKADAI), Japan. takemura@rs.kagu.tus.ac.jp
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.
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