UMass Chan Affiliations
Department of Cell BiologyDocument Type
Journal ArticlePublication Date
2005-09-14Keywords
AnimalsAntigens, Nuclear
Biological Transport
Cell Line
Centrosome
Cricetinae
Dyneins
Humans
Interphase
Leupeptins
Mice
Microtubules
Mitosis
Mitotic Spindle Apparatus
Nuclear Matrix-Associated Proteins
Nuclear Proteins
Proteasome Endopeptidase Complex
Protein Binding
Transcription, Genetic
Tubulin
Ubiquitin
Cell Biology
Metadata
Show full item recordAbstract
During interphase, the centrosome concentrates cell stress response molecules, including chaperones and proteasomes, into a proteolytic center. However, whether the centrosome functions as proteolytic center during mitosis is not known. In this study, cultured mammalian cells were treated with the proteasome inhibitor MG 132 and spindle morphology in mitotic cells was characterized in order to address this issue. Proteasome inhibition during mitosis leads to the formation of additional asters that cause the assembly of multipolar spindles. The cause of this phenomenon was investigated by inhibiting microtubule-based transport and protein synthesis. These experimental conditions prevented the formation of supernumerary asters during mitosis. In addition, the expression of dsRed without proteasome inhibition led to the fragmentation of spindle poles. These experiments showed that the formation of extra asters depends on intact microtubule-based transport and protein synthesis. These results suggest that formation of supernumerary asters is due to excessive accumulation of proteins at the spindle poles and consequently fragmentation of the centrosome. Together, this leads to the conclusion that the centrosome functions as proteolytic center during mitosis and proteolytic activity at the spindle poles is necessary for maintaining spindle pole integrity.Source
J Cell Physiol. 2005 Sep;204(3):808-18. Link to article on publisher's siteDOI
10.1002/jcp.20335Permanent Link to this Item
http://hdl.handle.net/20.500.14038/49034PubMed ID
15828030Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1002/jcp.20335