Cryo-electron tomography and proteomics identify a virus structure poised for genome uncoating

ABSTRACT: Viral infections invariably require the dismantling of capsids enclosing viral genomes. Yet, discrete intermediates and host factors supporting nucleic acid uncoating in susceptible cells are largely elusive. Using cryo-electron tomography (cryo-ET) and superresolution microscopy we show that human cells lacking the ubiquitin E3-ligase Mindbomb-1 (Mib1) deadlock adenovirus (AdV) particles at ~150nm radial distance from the nuclear pore complex (NPC). Cryo-ET revealed that the NPC-docked intermediate particles exhibit a central cavity in hexon trimers, the major capsid protein. Quantitative proteomics of isolated nuclei indicated that the intermediate particles bear reduced amounts of fiber and penton-base essential to attach the incoming virus particles to plasma membrane receptors, as well as reduced inner proteins VI and X used for endosomal membrane disruption and charge neutralization of viral DNA, respectively. The intermediate particles colocalized with the host nuclear export factor CRM1/exportin-1, independent of RanGTP hydrolysis required for CRM1 cargo export. They detached from the NPC upon CRM1 inhibition by the small compound leptomycin B, and redocked after inhibitor wash-out, indicating a tunable, direct function of CRM1 in NPC tethering of the intermediate particle poised for DNA uncoating. The results have implications on anti-viral strategies, gene therapy and synthetic biology.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human) Human Adenovirus C Serotype 5 (hadv-5) (human Adenovirus 5)

TISSUE(S): Epithelial Cell, Cell Culture

SUBMITTER: Alfonso Gomez Gonzalez  

LAB HEAD: Urs Greber

PROVIDER: PXD076818 | Pride | 2026-04-14

REPOSITORIES: Pride