Figure 1.

NDR1/2 regulate RIG-I-mediated innate immunity. RIG-I senses virus nucleic acids of viruses and activates downstream signaling pathways to initiate immune response. NDR2 directly associate with RIG-I and TRIM25, thus facilitating the formation of RIG-I/TRIM25 complex and enhancing the polyubiquitination of RIG-I. The ubiquitination of RIG-I further promotes the production of type I IFNs, so the antiviral immune response is enhanced. NDR1 promotes the activity of GSK3β. GSK3β promotes the activation of STAT1, then facilitates the expression of IFN-stimulated genes (ISGs). STAT1 is inhibited by miR146a. Binding to miR146a promoter, NDR1 inhibits NF-κB-mediated miR146a expression, and subsequently releases the inhibition of STAT1 expression by miR146a.