Mutual Repression by Bantam miRNA and Capicua Links the EGFR/MAPK and Hippo Pathways in Growth Control

SummaryBackgroundThe epidermal growth factor receptor (EGFR) and Hippo signaling pathways control cell proliferation and apoptosis to promote tissue growth during development. Misregulation of these pathways is implicated in cancer. Our understanding of the mechanisms that integrate the activity of these pathways remains fragmentary. This study identifies bantam microRNA as a common target of these pathways and suggests a mechanistic link between them.ResultsThe EGFR pathway acts through bantam to control tissue growth. bantam expression is regulated by the EGFR pathway, acting via repression of the transcriptional repressor Capicua. Thus EGFR signaling induces bantam expression by alleviating the effects of a repressor. bantam in turn acts in a negative feedback loop to limit Capicua expression.Conclusionsbantam appears to be a transcriptional target of both the EGFR and Hippo growth control pathways. Feedback regulation by bantam on Capicua provides a means to link signal propagation by the EGFR pathway to activity of the Hippo pathway and may play an important role in integration of these two pathways in growth control.

► Links the EGFR pathway and bantam microRNA in growth control and apoptosis
► Identifies Capicua as a target of both EGFR and the bantam microRNA
► Identifies a regulatory feedback network in tissue growth control