title: CDC25B associates with a centrin 2-containing complex and is involved in maintaining centrosome integrity.
abstract: BACKGROUND
  CDC25 (cell division cycle 25) phosphatases function as activators of CDK (cyclin-dependent kinase)-cyclin complexes to regulate progression through the CDC. We have recently identified a pool of CDC25B at the centrosome of interphase cells that plays a role in regulating centrosome numbers.
  
  
  RESULTS
  In the present study, we demonstrate that CDC25B forms a close association with Ctn (centrin) proteins at the centrosome. This interaction involves both N- and C-terminal regions of CDC25B and requires CDC25B binding to its CDK-cyclin substrates. However, the interaction is not dependent on the enzyme activity of CDC25B. Although CDC25B appears to bind indirectly to Ctn2, this association is pertinent to CDC25B localization at the centrosome. We further demonstrate that CDC25B plays a role in maintaining the overall integrity of the centrosome, by regulating the centrosome levels of multiple centrosome proteins, including that of Ctn2.
  
  
  CONCLUSIONS
  Our results therefore suggest that CDC25B associates with a Ctn2-containing multiprotein complex in the cytoplasm, which targets it to the centrosome, where it plays a role in maintaining the centrosome levels of Ctn2 and a number of other centrosome components.
authors.affiliation: Diamantina Institute, Princess Alexandra Hospital, The University of Queensland, Brisbane, Australia. rboutros@cmri.org.au
authors.forename: Rose
authors.initials: R
authors.lastname: Boutros
authors.forename: Corinne
authors.initials: C
authors.lastname: Lorenzo
authors.forename: Odile
authors.initials: O
authors.lastname: Mondesert
authors.forename: Alain
authors.initials: A
authors.lastname: Jauneau
authors.forename: Vanessa
authors.initials: V
authors.lastname: Oakes
authors.forename: Christine
authors.initials: C
authors.lastname: Dozier
authors.forename: Brian
authors.initials: B
authors.lastname: Gabrielli
authors.forename: Bernard
authors.initials: B
authors.lastname: Ducommun
mesh_terms: D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D018385:Centrosome / Q000737:chemistry / Q000378:metabolism*; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D020687:cdc25 Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: C472752:CETN2 protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; C517008:CDC25B protein, human; D020687:cdc25 Phosphatases