Deubiquitylation and stabilization of Acf7 by ubiquitin carboxylterminal hydrolase 14 (USP14) is critical for NSCLC migration.

The ubiquitin-proteasome system is an essential regulator of Acf7, which serves as a key effector for the maintenance of the EMT program and migration. However, the precise mechanism for the deubiquitination of Acf7 is still not fully understood. Using a proteomic approach, we identified ubiquitin-specific peptidase 14 (USP14) as an Acf7-associated deubiquitinase. Our findings show that there was an interaction between USP14 and Acf7. The expression of USP14 and Acf7 were elevated in lung cancer tissues compared to adjacent normal cells. Employing the overexpression of USP14 and the USP14 knockdown assay indicated that USP14 can greatly increase the steady-state levels of Acf7 by inhibiting the degradation of Acf7 through the ubiquitin- proteasome pathway. Here we identified USP14 as a deubiquitinating enzyme that regulated Acf7 ubiquitination and protein levels. Moreover, knockdown of USP14 inhibited cell migration, however, overexpression of wild-type USP14 but not USP14 mutants promoted cell migration. Together, these results suggest that USP14 plays an important role in the NSCLC migration through modulating Acf7 stability.