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Structural and biophysical characterizations of HIV-1 matrix trimer binding to lipid nanodiscs shed light on virus assembly
- Source :
- J Biol Chem, Repisalud, Instituto de Salud Carlos III (ISCIII)
- Publication Year :
- 2019
-
Abstract
- During the late phase of the HIV-1 replication cycle, the viral Gag polyproteins are targeted to the plasma membrane for assembly. The Gag-membrane interaction is mediated by binding of Gag's N-terminal myristoylated matrix (MA) domain to phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). The viral envelope (Env) glycoprotein is then recruited to the assembly sites and incorporated into budding particles. Evidence suggests that Env incorporation is mediated by interactions between Gag's MA domain and the cytoplasmic tail of the gp41 subunit of Env (gp41CT). MA trimerization appears to be an obligatory step for this interaction. Insufficient production of a recombinant MA trimer and unavailability of a biologically relevant membrane system have been barriers to detailed structural and biophysical characterization of the putative MA-gp41CT-membrane interactions. Here, we engineered a stable recombinant HIV-1 MA trimer construct by fusing a foldon domain (FD) of phage T4 fibritin to the MA C terminus. Results from NMR experiments confirmed that the FD attachment does not adversely alter the MA structure. Employing hydrogen-deuterium exchange MS, we identified an MA-MA interface in the MA trimer that is implicated in Gag assembly and Env incorporation. Utilizing lipid nanodiscs as a membrane mimetic, we show that the MA trimer binds to membranes 30-fold tighter than does the MA monomer and that incorporation of PI(4,5)P2 and phosphatidylserine enhances the binding of MA to nanodiscs. These findings advance our understanding of a fundamental mechanism in HIV-1 assembly and provide a template for investigating the interaction of MA with gp41CT. This work was supported by National Institutes of Health Grants 5R01GM117837 and 9R01AI150901 (to J.S.S.) Sí
- Subjects :
- 0301 basic medicine
Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)
Magnetic Resonance Spectroscopy
Protein subunit
viruses
Gene Products, gag
Myristoylated matrix (MA)
Trimer
Phosphatidylserines
Calorimetry
Phosphatidylserine (PS)
Gp41
Biochemistry
law.invention
03 medical and health sciences
Viral envelope
law
Nanodisc (ND)
Fab
Gag protein
Molecular Biology
Myristoylation
030102 biochemistry & molecular biology
Chemistry
C-terminus
Virus Assembly
Cell Membrane
Human immunodeficiency virus (HIV)
Cell Biology
Isothermal titration calorimetry (ITC)
Group-specific antigen
HIV Envelope Protein gp41
Mass spectrometry (MS)
030104 developmental biology
Protein Structure and Folding
Recombinant DNA
Biophysics
HIV-1
Nuclear magnetic resonance (NMR)
Plasma membrane
Protein Binding
Subjects
Details
- ISSN :
- 1083351X
- Volume :
- 294
- Issue :
- 49
- Database :
- OpenAIRE
- Journal :
- The Journal of biological chemistry
- Accession number :
- edsair.doi.dedup.....d4e08dfe5cb9e5021986ebdf737c1110