NRZ complex facilitates virus infection via enhancing ER-LD contacts.

Lipid droplets (LDs), originating from the ER, play critical roles in lipid metabolism. ER-LD contacts enable lipid exchange and support essential cellular processes. However, how viruses utilize ER-LD coordination remains elusive. Here, we demonstrate that hepatitis C virus (HCV) infection markedly increases LDs abundance and enhances ER-LD contacts. Through a targeted screen of ER-LD tethering proteins, we identified that the NRZ complex, composed of nonsteroidal anti-inflammatory drug-activated gene (NAG), RAD50 interactor 1 (RINT1) and zeste white 10 (ZW10), is essential for HCV-induced ER-LD association and viral infection. Mechanistically, RINT1 and ZW10 interact with the HCV envelope protein E1. Ectopic E1 expression is sufficient to promote ER-LD contacts, which are abolished upon NRZ depletion. NRZ depletion also impairs Dengue virus (DENV) and Zika virus (ZIKV) infection, suggesting its conserved proviral function. Together, this work uncovers a critical mechanism by which host inter-organelle tethering complexes regulate viral infection, offering new insights into virus-host interactions and potential antiviral targets.