title: Coxsackievirus can exploit LC3 in both autophagy-dependent and -independent manners in vivo.
abstract: RNA viruses modify intracellular membranes to produce replication scaffolds. In pancreatic cells, coxsackievirus B3 (CVB3) hijacks membranes from the autophagy pathway, and in vivo disruption of acinar cell autophagy dramatically delays CVB3 replication. This is reversed by expression of GFP-LC3, indicating that CVB3 may acquire membranes from an alternative, autophagy-independent, source(s). Herein, using 3 recombinant CVB3s (rCVB3s) encoding different proteins (proLC3, proLC3(G120A), or ATG4B(C74A)), we show that CVB3 is, indeed, flexible in its utilization of cellular membranes. When compared with a control rCVB3, all 3 viruses replicated to high titers in vivo, and caused severe pancreatitis. Most importantly, each virus appeared to subvert membranes in a unique manner. The proLC3 virus produced a large quantity of LC3-I which binds to phosphatidylethanolamine (PE), affording access to the autophagy pathway. The proLC3(G120A) protein cannot attach to PE, and instead binds to the ER-resident protein SEL1L, potentially providing an autophagy-independent source of membranes. Finally, the ATG4B(C74A) protein sequestered host cell LC3-I, causing accumulation of immature phagophores, and massive membrane rearrangement. Taken together, our data indicate that some RNA viruses can exploit a variety of different intracellular membranes, potentially maximizing their replication in each of the diverse cell types that they infect in vivo.
authors.affiliation: a Department of Immunology and Microbial Science; The Scripps Research Institute ; La Jolla , CA USA.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Alirezaei
authors.forename: Claudia T
authors.initials: CT
authors.lastname: Flynn
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Wood
authors.forename: Stephanie
authors.initials: S
authors.lastname: Harkins
authors.forename: J Lindsay
authors.initials: JL
authors.lastname: Whitton
mesh_terms: D000818:Animals; D001343:Autophagy; D000071183:Autophagy-Related Proteins; D003384:Coxsackievirus Infections / Q000821:virology*; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004770:Enterovirus / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006720:Homozygote; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D010179:Pancreas / Q000821:virology; D010714:Phosphatidylethanolamines / Q000737:chemistry; D011506:Proteins / Q000378:metabolism; D012328:RNA Viruses / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
chemical_list: D000071183:Autophagy-Related Proteins; D047908:Intracellular Signaling Peptides and Proteins; C480860:Map1lc3b protein, mouse; D008869:Microtubule-Associated Proteins; D010714:Phosphatidylethanolamines; D011506:Proteins; D011994:Recombinant Proteins; C492169:Sel1h protein, mouse; D014764:Viral Proteins; D049452:Green Fluorescent Proteins; C483858:phosphatidylethanolamine; C582881:Atg4b protein, mouse; D003546:Cysteine Endopeptidases
keywords: ER; ERAD; LC3; RNA virus; SEL1L; autophagy; coxsackievirus; enterovirus; membranes; pancreas