Figure 3. The daisy chain model for NEP-mediated nuclear export of influenza virus vRNPs.

The β-importin Crm1 mediates export of the vRNP complex by binding to the N-terminal domain of NEP, as well as to its cofactor, the small GTPase Ran. The C-terminus of NEP binds to the nuclear localisation signal (NLS) on the N-terminal domain of the viral matrix protein M1. The C-terminus of M1 in turn binds strongly to the vRNP through interaction with NP (grey).