Golgi-associated nuclear import receptor importin-7 targets HPV from the Golgi to the nucleus to promote infection
During human papillomavirus (HPV) entry, the virus exploits COPI-dependent retrograde transport to cross the trans-Golgi network and Golgi stacks before reaching the nucleus to cause infection. How HPV enters the nucleus after exiting the Golgi is unclear, although mitotic nuclear envelop breakdown (NEB) appears important. Here we show that importin-7 (IPO7), a nuclear pore import receptor, associates with the Golgi and promotes HPV infection. Upon IPO7 knockdown, HPV infection is inhibited and the virus accumulates in the Golgi but does not enter the nucleus, demonstrating that IPO7 promotes Golgi-to-nucleus transport of HPV. We further reveal that the C-terminus of HPV capsid protein L2, which is thought to contain overlapping nuclear localization and cell-penetrating peptide sequences, binds directly to IPO7 in a step that requires COPI-dependent virus trafficking. Together these data identify a role of an importin in HPV infection, raising the possibility that the canonical nuclear pore import machinery plays an unanticipated role in NEB-dependent nuclear entry. TeaserHPV, a cancer-causing human pathogen, exploits the Golgi-associated nuclear import receptor IPO7 for Golgi-to-nucleus trafficking to promote infection.