Identification of a role for beta-catenin in the establishment of a bipolar mitotic spindle.
beta-Catenin is a multifunctional protein that is known to participate in two well defined cellular processes, cell-cell adhesion and Wnt-stimulated transcriptional activation. Here we report that beta-catenin participates in a third cellular process, the establishment of a bipolar mitotic spindle. During mitosis, beta-catenin relocalizes to mitotic spindle poles and to the midbody. Furthermore, biochemical fractionation demonstrates the presence of beta-catenin in purified centrosome preparations. Reduction of cellular beta-catenin by RNA interference leads to the failure of centrosomes to fully separate, resulting in a marked increase in the frequency of monoastral mitotic spindles. Our results define a new and important function for beta-catenin in mitosis and demonstrate that beta-catenin is involved in vital biological processes beyond cell adhesion and Wnt signaling.
Kaplan
Daniel D
DD
Department of Pharmacology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Meigs
Thomas E
TE
Kelly
Patrick
P
Casey
Patrick J
PJ
D000818:Animals; D002460:Cell Line; D003598:Cytoskeletal Proteins / Q000502:physiology*; D006801:Humans; D034622:RNA Interference; D008941:Spindle Apparatus / Q000502:physiology*; D015534:Trans-Activators / Q000502:physiology*; D014981:Xenopus; D029867:Xenopus Proteins; D051176:beta Catenin
C495266:CTNNB1 protein, Xenopus; C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D029867:Xenopus Proteins; D051176:beta Catenin