Nucleolar modulation of TRF1: a dynamic way to regulate telomere and cell cycle by nucleostemin and GNL3L

Cell Cycle. 2009 Sep 15;8(18):2912-6. doi: 10.4161/cc.8.18.9543. Epub 2009 Sep 16.

Abstract

Chromosomal ends are protected by a high-order structure called telomere. Maintenance of correct telomere length and structure is critically important for the viability of both dividing and non-dividing cells. Notably, targeted deletion of a component of the multi-protein telomere-capping complex, TRF1 (telomeric repeat binding factor 1), causes lethality at embryonic day 5-6 without apparent telomere deficiency, raising the possibility that TRF1 may also moonlight outside the telomere. Further reinforcing the extra-telomeric tie of TRF1, two studies from our group have reported the findings that TRF1 can be bound and modulated by two nucleolar GTP-binding proteins, nucleostemin (NS) and guanine nucleotide binding protein-like 3-like (GNL3L), which exhibit apparently opposite effects on the protein degradation of TRF1. In particular, GNL3L is able to stabilize TRF1 protein during mitosis and promote the metaphase-to-anaphase transition. This manuscript extends the discussion on how this GNL3L-mediated TRF1 regulation creates a novel dynamic control on telomere and cell cycle, and extrapolates its evolutionary significance by contrasting the activities of NS and GNL3L.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Carrier Proteins / metabolism*
  • Cell Cycle
  • Cell Nucleolus
  • GTP-Binding Proteins / metabolism*
  • Humans
  • Nuclear Proteins / metabolism*
  • Telomere / metabolism
  • Telomeric Repeat Binding Protein 1 / metabolism*

Substances

  • Carrier Proteins
  • GNL3 protein, human
  • GNL3L protein, human
  • Nuclear Proteins
  • Telomeric Repeat Binding Protein 1
  • GTP-Binding Proteins