Stability of the small γ-tubulin complex requires HCA66, a protein of the centrosome and the nucleolus.

Fant, Xavier, Gnadt, Nicole, Haren, Laurence and Merdes, Andreas (2009) Stability of the small γ-tubulin complex requires HCA66, a protein of the centrosome and the nucleolus. Journal of Cell Science, 122 (8). pp. 1134-1144. ISSN 0021-9533

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To investigate changes at the centrosome during the cell cycle,
we analyzed the composition of the pericentriolar material
from unsynchronized and S-phase-arrested cells by gel
electrophoresis and mass spectrometry. We identified HCA66,
a protein that localizes to the centrosome from S-phase to mitosis
and to the nucleolus throughout interphase. Silencing of HCA66
expression resulted in failure of centrosome duplication
and in the formation of monopolar spindles, reminiscent
of the phenotype observed after γ-tubulin silencing.
Immunofluorescence microscopy showed that proteins of the
γ-tubulin ring complex were absent from the centrosome in
these monopolar spindles. Immunoblotting revealed reduced
protein levels of all components of the γ-tubulin small complex
(γ-tubulin, GCP2, and GCP3) in HCA66-depleted cells. By
contrast, the levels of γ-tubulin ring complex proteins such as
GCP4 and GCP-WD/NEDD1 were unaffected. We propose that
HCA66 is a novel regulator of γ-tubulin function that plays a
role in stabilizing components of the γ-tubulin small complex,
which is in turn essential for assembling the larger γ-tubulin
ring complex.

Item Type: Article
Print ISSN: 0021-9533
Electronic ISSN: 1477-9137
Uncontrolled Keywords: Centrosome; γ-Tubulin; Mitosis; Monopolar; Spindle;
University Divisions/Research Centres: Faculty of Health, Life & Social Sciences > School of Life Sciences
Dewey Decimal Subjects: 500 Science > 570 Life sciences; biology > 572 Biochemistry
Library of Congress Subjects: Q Science > QH Natural history > QH301 Biology
Item ID: 5484
Depositing User: Mrs Nicole Payton
Date Deposited: 22 Jun 2012 13:54
Last Modified: 08 Jan 2013 11:50

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