Disruption of desmosome function leads to increased centrosome clustering in 14-3-3γ-knockout cells with supernumerary centrosomes.

ABSTRACT

14-3-3 proteins are conserved, dimeric, acidic proteins that regulate multiple cellular pathways. Loss of either 14-3-3ε or 14-3-3γ leads to centrosome amplification. However, we find that while the knockout of 14-3-3ε leads to multipolar mitoses, the knockout of 14-3-3γ results in centrosome clustering and pseudo-bipolar mitoses. 14-3-3γ knockouts demonstrate compromised desmosome function and a decrease in keratin levels, leading to decreased cell stiffness and an increase in centrosome clustering. Restoration of desmosome function increased multipolar mitoses, whereas knockdown of either plakoglobin or keratin 5 led to decreased cell stiffness and increased pseudo-bipolar mitoses. These results suggest that the ability of the desmosome to anchor keratin filaments maintains cell stiffness, thus inhibiting centrosome clustering, and that phenotypes observed upon 14-3-3 loss reflect the dysregulation of multiple pathways.