Zimina, A.; Viktorova, E.G.; Moghimi, S.; Nchoutmboube, J.; Belov, G.A. Interaction of Poliovirus Capsid Proteins with the Cellular Autophagy Pathway. Viruses2021, 13, 1587.
Zimina, A.; Viktorova, E.G.; Moghimi, S.; Nchoutmboube, J.; Belov, G.A. Interaction of Poliovirus Capsid Proteins with the Cellular Autophagy Pathway. Viruses 2021, 13, 1587.
The capsid precursor P1 constitutes the N-terminal part of the enterovirus poly-protein. It is processed into VP0, VP3, and VP1 by the viral proteases, and VP0 is cleaved autocatalytically into VP4 and VP2. We observed that poliovirus VP0 is recognized by an antibody against a cellular autophagy protein LC3A. The LC3A-like epitope overlapped the VP4/VP2 cleavage site. Individually expressed VP0-EGFP and P1 strongly colocalized with a marker of selective autophagy p62/SQSTM1. To assess the role of capsid proteins in autophagy development we infected different cells with poliovirus or encapsidated polio replicon coding for only the replication proteins. We analyzed the processing of LC3B and p62/SQSTM1, markers of the initiation and completion of the autophagy pathway, and systematically investigated the association of the viral antigens with these au-tophagy proteins in infected cells. We observed cell-type specific development of autophagy upon infection and found that only the virion signal strongly co-localized with p62/SQSTM1 early in infection. Collectively, our data suggest that activation of autophagy is an antiviral response, and that capsid proteins con-tain determinants targeting them to p62/SQSTM1-dependent sequestration. Such a strategy may control the level of capsid proteins so that viral RNAs are not re-moved from the replication/translation pool prematurely.
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