TFCP2 Is Required for YAP-Dependent Transcription to Stimulate Liver Malignancy

Although YAP-dependent transcription is closely associated with liver tumorigenesis, the mechanism by which YAP maintains its function is poorly understood. Here, we show that TFCP2 is required for YAP-dependent transcription and liver malignancy. Mechanistically, YAP function is stimulated by TFCP2 via a WW-PSY interaction. TFCP2 also maintains YAP stability by inhibiting βTrCP. Notably, genomic co-occupancy of YAP and TFCP2 is revealed. TFCP2 acts as a transcription co-factor that stimulates YAP transcription by facilitating YAP binding with YAP binding motif (YBF)-containing transcription factors. Interestingly, TFCP2 also stimulated the YAP-TEAD interaction and TEAD target gene expression. Finally, several genes co-regulated by YAP and TFCP2 that contribute to YAP-dependent tumorigenesis are identified and verified. Thus, we establish a model showing that TFCP2 acts as a YAP co-factor to maintain YAP-dependent transcription in liver cancer cells, suggesting that simultaneous targeting of both YAP and TFCP2 may be an effective therapeutic approach.