Dynamin 2 binds gamma-tubulin and participates in centrosome cohesion

Nat Cell Biol. 2004 Apr;6(4):335-42. doi: 10.1038/ncb1112. Epub 2004 Mar 14.

Abstract

Dynamin 2 (Dyn2) is a large GTPase involved in vesicle formation and actin reorganization. In this study, we report a novel role for Dyn2 as a component of the centrosome that is involved in centrosome cohesion. By light microscopy, Dyn2 localized aside centrin and colocalized with gamma-tubulin at the centrosome; by immunoelectron microscopy, however, Dyn2 was detected in the pericentriolar material as well as on centrioles. Exogenously expressed green fluorescent protein (GFP)-tagged Dyn2 also localized to the centrosome, whereas glutathione S-transferase (GST)-tagged Dyn2 pulled down a protein complex(es) containing actin, alpha-tubulin and gamma-tubulin from liver homogenate. Furthermore, gel overlay and immunoprecipitation indicated a direct interaction between gamma-tubulin and a 219-amino-acid middle domain of Dyn2. Reduction of Dyn2 protein levels with small-interfering RNA (siRNA) resulted in centrosome splitting, whereas microtubule nucleation from centrosomes was not affected, suggesting a role for Dyn2 in centrosome cohesion. Finally, fluorescence recovery after photobleaching (FRAP) analysis of a GFP-tagged Dyn2 middle domain indicated that Dyn2 is a dynamic exchangeable component of the centrosome. These findings suggest a novel function for Dyn2 as a participant in centrosome cohesion.

MeSH terms

  • Actins / metabolism
  • Animals
  • Centrosome / metabolism*
  • Centrosome / ultrastructure
  • Dynamin II / genetics
  • Dynamin II / metabolism*
  • HeLa Cells
  • Humans
  • Immunohistochemistry
  • Microscopy, Electron
  • Microtubules / metabolism*
  • Microtubules / ultrastructure
  • Molecular Sequence Data
  • Protein Binding / physiology
  • Protein Structure, Tertiary / physiology
  • RNA Interference / physiology
  • Trimethoprim, Sulfamethoxazole Drug Combination / metabolism
  • Tubulin / metabolism*

Substances

  • Actins
  • Tubulin
  • Trimethoprim, Sulfamethoxazole Drug Combination
  • Dynamin II

Associated data

  • GENBANK/L25605