Alanine scanning mutagenesis of HIV-1 gp41 heptad repeat 1: insight into the gp120-gp41 interaction
- PMID: 20481578
- DOI: 10.1021/bi1005267
Alanine scanning mutagenesis of HIV-1 gp41 heptad repeat 1: insight into the gp120-gp41 interaction
Abstract
On the basis of mutagenesis, biochemical, and structural studies, heptad repeat 1 of HIV gp41 (HR1) has been shown to play numerous critical roles in HIV entry, including interacting with gp120 in prefusion states and interacting with gp41 heptad repeat 2 (HR2) in the fusion state. Moreover, HR1 is the site of therapeutic intervention by enfuviritide, a peptide analogue of HR2. In this study, the functional importance of each amino acid residue in gp41 HR1 has been systematically examined by alanine scanning mutagenesis, with subsequent characterization of the mutagenic effects on folding (as measured by incorporation into virions), association with gp120, and membrane fusion. The mutational effects on entry can be grouped into three classes: (1) wild type (defined as >40% of wild-type entry), (2) impaired (defined as 5-40% of wild-type entry), and (3) nonfunctional (defined as <5% of wild-type entry). Interestingly, the majority of HR1 mutations (77%) exhibit impaired or nonfunctional entry. Surprisingly, effects of mutations on folding, association, or fusion are not correlated to heptad position; however, folding defects are most often found in the N-terminal region of HR1. Moreover, disruption of the gp41-gp120 interaction is correlated to the C-terminal region of HR1, suggesting that this region interacts most closely with gp120. In summary, the sensitivity of gp41 HR1 to alanine substitutions suggests that even subtle changes in the local environment may severely affect envelope function, thereby strengthening the notion that HR1 is an attractive site for therapeutic intervention.
Similar articles
-
Functional analysis of the disulfide-bonded loop/chain reversal region of human immunodeficiency virus type 1 gp41 reveals a critical role in gp120-gp41 association.J Virol. 2001 Jul;75(14):6635-44. doi: 10.1128/JVI.75.14.6635-6644.2001. J Virol. 2001. PMID: 11413331 Free PMC article.
-
Mutations That Increase the Stability of the Postfusion gp41 Conformation of the HIV-1 Envelope Glycoprotein Are Selected by both an X4 and R5 HIV-1 Virus To Escape Fusion Inhibitors Corresponding to Heptad Repeat 1 of gp41, but the gp120 Adaptive Mutations Differ between the Two Viruses.J Virol. 2019 May 15;93(11):e00142-19. doi: 10.1128/JVI.00142-19. Print 2019 Jun 1. J Virol. 2019. PMID: 30894471 Free PMC article.
-
HIV-1 gp41 Residues Modulate CD4-Induced Conformational Changes in the Envelope Glycoprotein and Evolution of a Relaxed Conformation of gp120.J Virol. 2018 Jul 31;92(16):e00583-18. doi: 10.1128/JVI.00583-18. Print 2018 Aug 15. J Virol. 2018. PMID: 29875245 Free PMC article.
-
The hydrophobic pocket contributes to the structural stability of the N-terminal coiled coil of HIV gp41 but is not required for six-helix bundle formation.Biochemistry. 2003 May 6;42(17):4945-53. doi: 10.1021/bi027283n. Biochemistry. 2003. PMID: 12718536
-
C peptides as entry inhibitors for gene therapy.Adv Exp Med Biol. 2015;848:191-209. doi: 10.1007/978-1-4939-2432-5_10. Adv Exp Med Biol. 2015. PMID: 25757622 Review.
Cited by
-
Deep Mutational Scanning of Viral Glycoproteins and Their Host Receptors.Front Mol Biosci. 2021 Apr 9;8:636660. doi: 10.3389/fmolb.2021.636660. eCollection 2021. Front Mol Biosci. 2021. PMID: 33898517 Free PMC article. Review.
-
Cell-cell and virus-cell fusion assay-based analyses of alanine insertion mutants in the distal α9 portion of the JRFL gp41 subunit from HIV-1.J Biol Chem. 2019 Apr 5;294(14):5677-5687. doi: 10.1074/jbc.RA118.004579. Epub 2019 Feb 8. J Biol Chem. 2019. PMID: 30737278 Free PMC article.
-
Significant differences in cell-cell fusion and viral entry between strains revealed by scanning mutagenesis of the C-heptad repeat of HIV gp41.Biochemistry. 2013 May 21;52(20):3552-63. doi: 10.1021/bi400201h. Epub 2013 May 7. Biochemistry. 2013. PMID: 23621782 Free PMC article.
-
Molecular architecture of the uncleaved HIV-1 envelope glycoprotein trimer.Proc Natl Acad Sci U S A. 2013 Jul 23;110(30):12438-43. doi: 10.1073/pnas.1307382110. Epub 2013 Jun 11. Proc Natl Acad Sci U S A. 2013. PMID: 23757493 Free PMC article.
-
Striking HIV-1 Entry by Targeting HIV-1 gp41. But, Where Should We Target?PLoS One. 2016 Jan 19;11(1):e0146743. doi: 10.1371/journal.pone.0146743. eCollection 2016. PLoS One. 2016. PMID: 26785380 Free PMC article.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources