title: Low pH and Anionic Lipid-dependent Fusion of Uukuniemi Phlebovirus to Liposomes.
abstract: Many phleboviruses (family Bunyaviridae) are emerging as medically important viruses. These viruses enter target cells by endocytosis and low pH-dependent membrane fusion in late endosomes. However, the necessary and sufficient factors for fusion have not been fully characterized. We have studied the minimal fusion requirements of a prototypic phlebovirus, Uukuniemi virus, in an in vitro virus-liposome assay. We show that efficient lipid mixing between viral and liposome membranes requires close to physiological temperatures and phospholipids with negatively charged headgroups, such as the late endosomal phospholipid bis(monoacylglycero)phosphate. We further demonstrate that bis(monoacylglycero)phosphate increases Uukuniemi virus fusion beyond the lipid mixing stage. By using electron cryotomography of viral particles in the presence or absence of liposomes, we observed that the conformation of phlebovirus glycoprotein capsomers changes from the native conformation toward a more elongated conformation at a fusion permissive pH. Our results suggest a rationale for phlebovirus entry in late endosomes.
authors.affiliation: From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford OX3 7BN, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Bitto
authors.affiliation: From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford OX3 7BN, United Kingdom.
authors.forename: Steinar
authors.initials: S
authors.lastname: Halldorsson
authors.affiliation: From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford OX3 7BN, United Kingdom.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Caputo
authors.affiliation: From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford OX3 7BN, United Kingdom juha@strubi.ox.ac.uk.
authors.forename: Juha T
authors.identifier: http://orcid.org/0000-0002-0348-7323
authors.initials: JT
authors.lastname: Huiskonen
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D006023:Glycoproteins / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000737:chemistry*; D008246:Lysophospholipids / Q000737:chemistry*; D050178:Monoglycerides / Q000737:chemistry*; D016856:Phlebovirus / Q000737:chemistry* / Q000502:physiology; D014764:Viral Proteins / Q000502:physiology; D053586:Virus Internalization
chemical_list: D006023:Glycoproteins; D008081:Liposomes; D008246:Lysophospholipids; D050178:Monoglycerides; D014764:Viral Proteins; C012786:bis(monoacylglyceryl)phosphate
keywords: bis(monoacylglycero)phosphate; bunyavirus; electron tomography; membrane; membrane fusion; phlebovirus; virus entry; virus structure
references.citation: J Vis Exp. 2014;(92):e51714
references.pmid: 25350719
references.citation: J Struct Biol. 2005 Oct;152(1):36-51
references.pmid: 16182563
references.citation: Virology. 2000 Mar 30;269(1):37-46
references.pmid: 10725196
references.citation: Cell. 2001 Apr 6;105(1):137-48
references.pmid: 11301009
references.citation: J Biol Chem. 2002 Aug 30;277(35):32157-64
references.pmid: 12065580
references.citation: Traffic. 2003 Apr;4(4):222-31
references.pmid: 12694561
references.citation: Proc Natl Acad Sci U S A. 2003 Jun 10;100(12):6986-91
references.pmid: 12759475
references.citation: Biophys J. 2003 Sep;85(3):1667-74
references.pmid: 12944281
references.citation: Virology. 1972 Dec;50(3):899-901
references.pmid: 4344945
references.citation: J Cell Biol. 1980 Feb;84(2):404-20
references.pmid: 6991511
references.citation: J Mol Biol. 1980 Sep 25;142(3):439-54
references.pmid: 7463480
references.citation: Lancet Infect Dis. 2006 Apr;6(4):203-14
references.pmid: 16554245
references.citation: Proc Natl Acad Sci U S A. 2008 Feb 19;105(7):2375-9
references.pmid: 18272496
references.citation: Chem Phys Lipids. 2008 Jul;154(1):64-7
references.pmid: 18405663
references.citation: Nat Struct Mol Biol. 2008 Jul;15(7):675-83
references.pmid: 18596814
references.citation: Nat Struct Mol Biol. 2008 Jul;15(7):690-8
references.pmid: 18596815
references.citation: J Virol. 2008 Sep;82(18):9245-53
references.pmid: 18632857
references.citation: Proc Natl Acad Sci U S A. 2008 Oct 7;105(40):15382-7
references.pmid: 18829437
references.citation: J Virol. 2008 Nov;82(21):10341-8
references.pmid: 18715915
references.citation: PLoS Pathog. 2008 Dec;4(12):e1000244
references.pmid: 19096510
references.citation: Nat Protoc. 2009;4(3):363-71
references.pmid: 19247286
references.citation: J Virol. 2009 Apr;83(8):3762-9
references.pmid: 19193794
references.citation: Virology. 2009 Apr 25;387(1):11-5
references.pmid: 19304307
references.citation: EMBO J. 2010 Apr 7;29(7):1299-311
references.pmid: 20168302
references.citation: FEBS Lett. 2010 May 3;584(9):1700-12
references.pmid: 19836391
references.citation: J Virol. 2010 May;84(10):4889-97
references.pmid: 20219926
references.citation: Cell Host Microbe. 2010 Jun 25;7(6):488-99
references.pmid: 20542252
references.citation: Annu Rev Biochem. 2003;72:175-207
references.pmid: 14527322
references.citation: Proc Natl Acad Sci U S A. 1969 Oct;64(2):536-43
references.pmid: 5261030
references.citation: PLoS Pathog. 2010;6(10):e1001131
references.pmid: 20949067
references.citation: N Engl J Med. 2011 Apr 21;364(16):1523-32
references.pmid: 21410387
references.citation: Cell Host Microbe. 2011 Jul 21;10(1):75-88
references.pmid: 21767814
references.citation: Proc Natl Acad Sci U S A. 2011 Jul 19;108(29):E304-13
references.pmid: 21705659
references.citation: Neurochem Res. 2011 Sep;36(9):1594-600
references.pmid: 21136156
references.citation: J Gen Virol. 2011 Nov;92(Pt 11):2467-84
references.pmid: 21865443
references.citation: PLoS Pathog. 2011 Nov;7(11):e1002369
references.pmid: 22114553
references.citation: Viruses. 2011 May;3(5):493-519
references.pmid: 21666766
references.citation: Antiviral Res. 2012 Aug;95(2):82-7
references.pmid: 22684044
references.citation: J Virol. 2012 Dec;86(23):12954-70
references.pmid: 22993156
references.citation: J Virol. 2012 Dec;86(24):13642-52
references.pmid: 23035232
references.citation: Proc Natl Acad Sci U S A. 2013 Jan 29;110(5):1696-701
references.pmid: 23319635
references.citation: Cell Host Microbe. 2013 Apr 17;13(4):452-64
references.pmid: 23601107
references.citation: PLoS Pathog. 2013;9(5):e1003374
references.pmid: 23696739
references.citation: Proc Natl Acad Sci U S A. 2013 Aug 13;110(33):13362-7
references.pmid: 23898184
references.citation: Mol Cell Biol. 1982 Nov;2(11):1444-58
references.pmid: 6891745
references.citation: Biochemistry. 1988 Jan 12;27(1):30-6
references.pmid: 2831956
references.citation: J Gen Virol. 1990 Mar;71 ( Pt 3):501-22
references.pmid: 2179464
references.citation: J Virol. 1992 Dec;66(12):7309-18
references.pmid: 1433520
references.citation: EMBO J. 1993 Feb;12(2):693-701
references.pmid: 8440260
references.citation: EMBO J. 1994 Jun 15;13(12):2797-804
references.pmid: 8026464
references.citation: J Virol. 1995 May;69(5):3220-3
references.pmid: 7707555
references.citation: Nature. 1995 May 25;375(6529):291-8
references.pmid: 7753193
references.citation: J Struct Biol. 1996 Jan-Feb;116(1):71-6
references.pmid: 8742726
references.citation: Trends Microbiol. 1998 Jan;6(1):31-5
references.pmid: 9481822
references.citation: J Cell Biol. 1998 Mar 23;140(6):1369-82
references.pmid: 9508770
references.citation: J Virol. 1999 Oct;73(10):8476-84
references.pmid: 10482600
references.citation: Biochemistry. 2005 Feb 15;44(6):2097-102
references.pmid: 15697235
references.citation: J Virol. 2005 Jun;79(12):7942-8
references.pmid: 15919953
references.citation: Nat Rev Mol Cell Biol. 2008 Feb;9(2):112-24
references.pmid: 18216768