TY - JOUR
T1 - p34cdc2-mediated phosphorylation mobilizes microtubule-organizing centers from the apical intermediate filament scaffold in CACO-2 epithelial cells
AU - Figueroa, Yolanda
AU - Wald, Flavia A.
AU - Salas, Pedro J.I.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/10/4
Y1 - 2002/10/4
N2 - We have shown previously that centrosomes and other microtubule-organizing centers (MTOCs) attach to the apical intermediate filament (IF) network in CACO-2 cells. In this cell line, intermediate filaments do not disorganize during mitosis. Therefore, we speculated that the trigger of the G2-M boundary may also detach MTOCs from their IF anchor. If that was the case, at least one of the proteins involved in the attachment must be phosphorylated by p34cdc2 (cdk1). Using confocal microscopy and standard biochemical analysis, we found that p34cdc2-mediated phosphorylation indeed released MTOCs from IFs in permeabilized cells. In isolated, immunoprecipitated multiprotein complexes containing both γ-tubulin and cytokeratin 19, p34cdc2 phosphorylated only one protein, and phosphorylation released cytokeratin 19 from the complexes. We conclude that this as yet unidentified protein is a part of the molecular mechanism that attaches MTOCs to IFs in interphase.
AB - We have shown previously that centrosomes and other microtubule-organizing centers (MTOCs) attach to the apical intermediate filament (IF) network in CACO-2 cells. In this cell line, intermediate filaments do not disorganize during mitosis. Therefore, we speculated that the trigger of the G2-M boundary may also detach MTOCs from their IF anchor. If that was the case, at least one of the proteins involved in the attachment must be phosphorylated by p34cdc2 (cdk1). Using confocal microscopy and standard biochemical analysis, we found that p34cdc2-mediated phosphorylation indeed released MTOCs from IFs in permeabilized cells. In isolated, immunoprecipitated multiprotein complexes containing both γ-tubulin and cytokeratin 19, p34cdc2 phosphorylated only one protein, and phosphorylation released cytokeratin 19 from the complexes. We conclude that this as yet unidentified protein is a part of the molecular mechanism that attaches MTOCs to IFs in interphase.
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U2 - 10.1074/jbc.M207037200
DO - 10.1074/jbc.M207037200
M3 - Article
C2 - 12151413
AN - SCOPUS:0037019831
VL - 277
SP - 37848
EP - 37854
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 40
ER -