GSBS Student Publications

Title

Cytoplasmic dynein-mediated assembly of pericentrin and gamma tubulin onto centrosomes

UMMS Affiliation

Graduate School of Biomedical Sciences; Program in Molecular Medicine; Department of Physiology

Date

6-10-2000

Document Type

Article

Medical Subject Headings

Animals; Antigens; CHO Cells; COS Cells; Centrosome; Cricetinae; Cytoplasm; Dynein ATPase; Green Fluorescent Proteins; Luminescent Proteins; Microtubule-Associated Proteins; Microtubules; Recombinant Fusion Proteins; Tubulin; Xenopus

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Centrosome assembly is important for mitotic spindle formation and if defective may contribute to genomic instability in cancer. Here we show that in somatic cells centrosome assembly of two proteins involved in microtubule nucleation, pericentrin and gamma tubulin, is inhibited in the absence of microtubules. A more potent inhibitory effect on centrosome assembly of these proteins is observed after specific disruption of the microtubule motor cytoplasmic dynein by microinjection of dynein antibodies or by overexpression of the dynamitin subunit of the dynein binding complex dynactin. Consistent with these observations is the ability of pericentrin to cosediment with taxol-stabilized microtubules in a dynein- and dynactin-dependent manner. Centrosomes in cells with reduced levels of pericentrin and gamma tubulin have a diminished capacity to nucleate microtubules. In living cells expressing a green fluorescent protein-pericentrin fusion protein, green fluorescent protein particles containing endogenous pericentrin and gamma tubulin move along microtubules at speeds of dynein and dock at centrosomes. In Xenopus extracts where gamma tubulin assembly onto centrioles can occur without microtubules, we find that assembly is enhanced in the presence of microtubules and inhibited by dynein antibodies. From these studies we conclude that pericentrin and gamma tubulin are novel dynein cargoes that can be transported to centrosomes on microtubules and whose assembly contributes to microtubule nucleation.

Rights and Permissions

Citation: Mol Biol Cell. 2000 Jun;11(6):2047-56.

Related Resources

Link to Article in PubMed

Journal Title

Molecular biology of the cell

PubMed ID

10848628