title: Autophagic clearance of Sin Nombre hantavirus glycoprotein Gn promotes virus replication in cells.
abstract: Hantavirus glycoprotein precursor (GPC) is posttranslationally cleaved into two glycoproteins, Gn and Gc. Cells transfected with plasmids expressing either GPC or both Gn and Gc revealed that Gn is posttranslationally degraded. Treatment of cells with the autophagy inhibitors 3-methyladenine, LY-294002, or Wortmanin rescued Gn degradation, suggesting that Gn is degraded by the host autophagy machinery. Confocal microscopic imaging showed that Gn is targeted to autophagosomes for degradation by an unknown mechanism. Examination of autophagy markers LC3-I and LC3-II demonstrated that both Gn expression and Sin Nombre hantavirus (SNV) infection induce autophagy in cells. To delineate whether induction of autophagy and clearance of Gn play a role in the virus replication cycle, we downregulated autophagy genes BCLN-1 and ATG7 using small interfering RNA (siRNA) and monitored virus replication over time. These studies revealed that inhibition of host autophagy machinery inhibits Sin Nombre virus replication in cells, suggesting that autophagic clearance of Gn is required for efficient virus replication. Our studies provide mechanistic insights into viral pathogenesis and reveal that SNV exploits the host autophagy machinery to decrease the intrinsic steady-state levels of an important viral component for efficient replication in host cells.
authors.affiliation: Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, USA.
authors.forename: Islam T M
authors.initials: IT
authors.lastname: Hussein
authors.forename: Erdong
authors.initials: E
authors.lastname: Cheng
authors.forename: Safder S
authors.initials: SS
authors.lastname: Ganaie
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Werle
authors.forename: Sheema
authors.initials: S
authors.lastname: Sheema
authors.forename: Absarul
authors.initials: A
authors.lastname: Haque
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Mir
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001343:Autophagy / Q000187:drug effects; D000071193:Autophagy-Related Protein 7; D002460:Cell Line; D002522:Chlorocebus aethiops; D002867:Chromones / Q000494:pharmacology; D006023:Glycoproteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D059748:Proteolysis; D034622:RNA Interference; D034741:RNA, Small Interfering; D029261:Sin Nombre virus / Q000502:physiology*; D044764:Ubiquitin-Activating Enzymes / Q000235:genetics / Q000378:metabolism; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000378:metabolism*; D014779:Virus Replication; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D002867:Chromones; D006023:Glycoproteins; D009025:Morpholines; D034741:RNA, Small Interfering; D014759:Viral Envelope Proteins; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C025946:3-methyladenine; C509349:ATG7 protein, human; D000071193:Autophagy-Related Protein 7; D044764:Ubiquitin-Activating Enzymes; D000225:Adenine; D000077191:Wortmannin