title: The membrane proximal external regions of gp41 from HIV-1 strains HXB2 and JRFL have different sensitivities to alanine mutation.
abstract: The transmembrane subunit (gp41) of the HIV envelope protein complex (Env) mediates the viral fusion step of HIV entry. The membrane proximal external region (MPER), one of the functional domains of gp41, has been the focus of a great deal of research because it is a target for neutralizing antibodies. In this study, we examined 23 amino acid residues in the MPER (660-683) in both a CXCR4 coreceptor-utilizing strain (HXB2) and a CCR5-utilizing strain (JRFL) by alanine scanning mutagenesis. Despite the high degree of gp41 sequence conservation, the effects of alanine mutation in the MPER were different between the two strains. Most mutations in HXB2 had fusogenicity and protein expression levels not less than 50% of that of the wild type in the case of cell-cell fusion. However, ∼30% of the mutants in HXB2 showed a severe defect in fusogenicity in viral entry. Mutations in the MPER of strain JRFL had more dramatic effects than that in HXB2 in cell-cell fusion and viral entry. The fact that there are large differences in the effects of mutation between two strains suggests the potential for the interaction of the MPER with nonconserved sequences such as the fusion peptide and/or other NHR domains as well as potential long-range structural effects on the conformational changes that occur with the Env complex during membrane fusion.
authors: Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York , Buffalo, New York 14214, United States.
authors: Hyun Ah
authors: HA
authors: Yi
authors: Barbara
authors: B
authors: Diaz-Rohrer
authors: Priyanka
authors: P
authors: Saminathan
authors: Amy
authors: A
authors: Jacobs
mesh_terms: D000409:Alanine / Q000235:genetics / Q000378:metabolism; D019943:Amino Acid Substitution; D002460:Cell Line; D015700:HIV Envelope Protein gp41 / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D008561:Membrane Fusion; D020125:Mutation, Missense; D017434:Protein Structure, Tertiary; D019713:Receptors, CCR5 / Q000235:genetics / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D053586:Virus Internalization
chemical_list: C584933:CCR5 protein, human; C527276:CXCR4 protein, human; D015700:HIV Envelope Protein gp41; D019713:Receptors, CCR5; D019718:Receptors, CXCR4; C514787:gp41 protein, Human immunodeficiency virus 1; D000409:Alanine
references: Cell. 2009 May 1;137(3):433-44
references: 19410541
references: J Virol. 1990 Apr;64(4):1690-7
references: 2157051
references: PLoS Pathog. 2012;8(4):e1002634
references: 22496655
references: Retrovirology. 2014;11:83
references: 25700025
references: PLoS Pathog. 2010 May;6(5):e1000880
references: 20463810
references: EMBO J. 1988 Feb;7(2):513-8
references: 3259178
references: J Virol. 1998 Apr;72(4):2855-64
references: 9525605
references: J Virol. 1995 Nov;69(11):6705-11
references: 7474080
references: Cell. 1997 Apr 18;89(2):263-73
references: 9108481
references: J Virol. 2000 Nov;74(21):10074-80
references: 11024136
references: Biochim Biophys Acta. 2001 May 31;1536(2-3):116-22
references: 11406346
references: Biochemistry. 2010 Jun 22;49(24):5057-65
references: 20481578
references: Biochemistry. 2007 Feb 6;46(5):1398-401
references: 17260969
references: J Virol. 1999 Jul;73(7):6089-92
references: 10364363
references: Virology. 2011 Apr 10;412(2):441-7
references: 21334707
references: AIDS Res Hum Retroviruses. 1994 Apr;10(4):371-81
references: 8068416
references: J Virol. 2004 Dec;78(23):13232-52
references: 15542675
references: Proc Natl Acad Sci U S A. 1997 Nov 11;94(23):12303-8
references: 9356444
references: J Biol Chem. 2013 Nov 1;288(44):31888-901
references: 24047898
references: Protein Pept Lett. 2006;13(5):477-80
references: 16800801
references: Biochemistry. 2011 Aug 16;50(32):6966-72
references: 21736372
references: Nat Immunol. 2004 Mar;5(3):233-6
references: 14985706
references: Proc Natl Acad Sci U S A. 1998 Aug 4;95(16):9134-9
references: 9689046
references: Nat Med. 2000 Feb;6(2):207-10
references: 10655111
references: Proc Natl Acad Sci U S A. 2010 Oct 19;107(42):17880-7
references: 20876137
references: J Virol. 2001 Nov;75(22):10892-905
references: 11602729
references: Eur J Biochem. 2004 Apr;271(8):1566-79
references: 15066182
references: Nat Struct Biol. 1995 Dec;2(12):1075-82
references: 8846219
references: PLoS One. 2014;9(7):e99881
references: 24992528
references: EMBO J. 1998 Aug 17;17(16):4572-84
references: 9707417
references: Biochemistry. 2013 May 21;52(20):3552-63
references: 23621782
references: PLoS One. 2011;6(9):e23532
references: 21980336
references: J Virol. 2004 Oct;78(19):10724-37
references: 15367639
references: J Virol. 1990 Nov;64(11):5270-6
references: 2214018
references: Proc Natl Acad Sci U S A. 2008 Mar 11;105(10):3739-44
references: 18322015
references: Open Virol J. 2011;5:44-51
references: 21660189
references: Microbiol Mol Biol Rev. 2008 Mar;72(1):54-84, table of contents
references: 18322034
references: Cell. 1987 Jun 5;49(5):659-68
references: 3107838
references: AIDS Res Hum Retroviruses. 1993 Nov;9(11):1051-3
references: 8312047
references: J Virol. 2007 Apr;81(8):4033-43
references: 17287272
references: Trends Microbiol. 2011 Apr;19(4):191-7
references: 21377881
references: AIDS Res Hum Retroviruses. 2001 Dec 10;17(18):1757-65
references: 11788027
references: Nat Rev Microbiol. 2008 Feb;6(2):143-55
references: 18197170
references: J Virol. 1993 Nov;67(11):6642-7
references: 7692082
references: Proc Natl Acad Sci U S A. 2009 Jun 2;106(22):9057-62
references: 19458040
references: PLoS Med. 2008 Jan 3;5(1):e9
references: 18177204
references: J Virol Methods. 1994 Jun;48(1):43-52
references: 7962259
references: J Virol. 2002 Aug;76(15):7760-76
references: 12097589
references: Nat Struct Biol. 1998 Apr;5(4):276-9
references: 9546217
references: J Biol Chem. 2005 Jul 22;280(29):27284-8
references: 15917239
references: Immunity. 2008 Jan;28(1):52-63
references: 18191596
references: Nature. 1997 May 22;387(6631):426-30
references: 9163431
references: Nature. 2012 Nov 15;491(7424):406-12
references: 23151583
references: J Virol. 2005 Jan;79(2):1252-61
references: 15613352
references: J Virol. 1993 May;67(5):2747-55
references: 8474172
references: J Virol. 1999 May;73(5):4009-18
references: 10196297
references: Proc Natl Acad Sci U S A. 2009 Dec 1;106(48):20234-9
references: 19906992
references: Nat Struct Mol Biol. 2011 Nov;18(11):1235-43
references: 22002224
references: J Virol. 1992 Nov;66(11):6547-54
references: 1404602
references: J Virol. 1999 Mar;73(3):2469-80
references: 9971832
references: Biophys J. 2014 Feb 4;106(3):610-20
references: 24507601
references: Proc Natl Acad Sci U S A. 1994 Oct 11;91(21):9770-4
references: 7937889
references: J Virol. 2012 Jul;86(14):7484-95
references: 22553332
references: J Biol Chem. 2010 Jul 30;285(31):24290-8
references: 20525690
references: J Virol. 2010 Jan;84(1):201-9
references: 19846514
references: Gene Ther. 1999 May;6(5):715-28
references: 10505094
references: Proc Natl Acad Sci U S A. 2014 Jan 28;111(4):1391-6
references: 24474763
references: J Virol. 2011 Aug;85(16):8217-26
references: 21653673