title: Dynamin 2 binds gamma-tubulin and participates in centrosome cohesion.
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.
authors.affiliation: Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Thompson
authors.forename: Hong
authors.initials: H
authors.lastname: Cao
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Ursula
authors.initials: U
authors.lastname: Euteneuer
authors.forename: Mark A
authors.initials: MA
authors.lastname: McNiven
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D018385:Centrosome / Q000378:metabolism* / Q000648:ultrastructure; D034285:Dynamin II / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D034622:RNA Interference / Q000502:physiology; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism*
chemical_list: D000199:Actins; D014404:Tubulin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D034285:Dynamin II