1. Phosphorylation of HPV-16 L2 Contributes To Efficient Virus Infectious EntryJustyna Broniarczyk, Paola Massimi, David Pim, Martina Bergant Marušič, Michael P. Myers, Robert L. Garcea, Lawrence Banks, 2019, izvirni znanstveni članek Opis: The Human Papillomavirus (HPV) capsid comprises two viral proteins, L1 and L2, with the L2 component being essential to ensure efficient endocytic transport of incoming viral genomes. Several studies have previously reported that L1 and L2 are post-translationally modified, but it is uncertain whether these modifications affect HPV infectious entry. Using a proteomic screen, we identified a highly conserved phospho-acceptor site on the HPV-16 and BPV-1 L2 proteins. The phospho-modification of L2, and its presence in HPV pseudovirions (PsVs), was confirmed using anti-phospho L2-specific antibodies. Mutation of the phospho-acceptor sites of both HPV-16 and BPV-1 L2 resulted in the production of infectious virus particles, with no differences in efficiency of packaging the reporter DNA. However, these mutated PsVs showed marked defects in infectious entry. Further analysis revealed a defect in uncoating, characterized by a delay in the exposure of a conformational epitope on L1 that indicates capsid uncoating. This uncoating defect was accompanied by a delay in the proteolysis of both L1 and L2 in mutated HPV-16 PsVs. Taken together, these studies indicate that phosphorylation of L2 during virus assembly plays an important role in optimal uncoating of virions during infection, suggesting that phosphorylation of the viral capsid proteins contributes to infectious entry. Ključne besede: HPV, L2, infection, protein phosphorylation Objavljeno v RUNG: 05.06.2019; Ogledov: 4153; Prenosov: 0 Gradivo ima več datotek! Več... |
2. Characterizing the spatio-temporal role of sorting nexin 17 in human papillomavirus traffickingMartina Bergant Marušič, Špela Peternel, David Pim, Justyna Broniarczyk, Lawrence Banks, 2017, izvirni znanstveni članek Ključne besede: HPV, L2, intracellular trafficking, sorting nexin 17, capsid disassembly Objavljeno v RUNG: 23.05.2017; Ogledov: 4953; Prenosov: 0 Gradivo ima več datotek! Več... |
3. The VPS4 component of the ESCRT machinery plays an essential role in HPV infectious entry and capsid disassemblyJustyna Broniarczyk, David Pim, Paola Massimi, Martina Bergant Marušič, Anna Gozdzicka-Jozefiak, Colin Crump, Lawrence Banks, 2017, izvirni znanstveni članek Opis: Human Papillomavirus (HPV) infection involves multiple steps, from cell attachment, through endocytic trafficking towards the trans-Golgi network, and, ultimately, the entry into the nucleus during mitosis. An essential viral protein in infectious entry is the minor capsid protein L2, which engages different components of the endocytic sorting machinery during this process. The ESCRT machinery is one such component that seems to play an important role in the early stages of infection. Here we have analysed the role of specific ESCRT components in HPV infection, and we find an essential role for VPS4. Loss of VPS4 blocks infection with multiple PV types, suggesting an evolutionarily conserved critical step in infectious entry. Intriguingly, both L1 and L2 can interact with VPS4, and appear to be in complex with VPS4 during the early stages of virus infection. By using cell lines stably expressing a dominant-negative mutant form of VPS4, we also show that loss of VPS4 ATPase activity results in a marked delay in capsid uncoating, resulting in a defect in the endocytic transport of incoming PsVs. These results demonstrate that the ESCRT machinery, and in particular VPS4, plays a critical role in the early stages of PV infection. Ključne besede: HPV, ESCRT machinery, infection Objavljeno v RUNG: 08.05.2017; Ogledov: 5108; Prenosov: 278 Celotno besedilo (1,10 MB) |
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