Cytoplasmic accumulation of cdc25B phosphatase in mitosis triggers centrosomal microtubule nucleation in HeLa cells.
J Cell Sci
; 109 ( Pt 5): 1081-93, 1996 May.
Article
in En
| MEDLINE
| ID: mdl-8743955
ABSTRACT
The formation of the mitotic spindle is an essential prerequisite for successful mitosis. The dramatic changes in the level of microtubule (Mt) nucleation at the centrosomes and Mt dynamics that occur in prophase are presumed to be initiated through the activity of cdc2/cyclin B. Here we present data that the cdc25B isoform functions to activate the cytoplasmic pool of cdc2/cyclin B responsible for these events. In contrast to cdc25C, cdc25B is present at low levels in HeLa cells during interphase, but sharply increases in prophase, when cdc25B accumulation in the cytoplasm correlates with prophase spindle formation. Overexpression of wild type and dominant negative mutants of cdc25B and cdc25C shows that prophase Mt nucleation is a consequence of cytoplasmic cdc25B activity, and that cdc25C regulates nuclear G2/M events. Our data also suggest that the functional status of the centrosome can regulate nuclear mitotic events.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
G2 Phase
/
Phosphoprotein Phosphatases
/
Centrosome
/
Cell Cycle Proteins
/
Cdc25 Phosphatases
/
Cytoplasm
/
Metaphase
/
Microtubules
/
Spindle Apparatus
Limits:
Humans
Language:
En
Journal:
J Cell Sci
Year:
1996
Document type:
Article
Affiliation country:
Australia