title: Dengue virus NS4A cytoplasmic domain binding to liposomes is sensitive to membrane curvature.
abstract: Dengue virus (DENV) infection is a growing public health threat with more than one-third of the world's population at risk. Non-structural protein 4A (NS4A), one of the least characterized viral proteins, is a highly hydrophobic transmembrane protein thought to induce the membrane alterations that harbor the viral replication complex. The NS4A N-terminal (amino acids 1-48), has been proposed to contain an amphipathic α-helix (AH). Mutations (L6E; M10E) designed to reduce the amphipathic character of the predicted AH, abolished viral replication and reduced NS4A oligomerization. Nuclear magnetic resonance (NMR) spectroscopy was used to characterize the N-terminal cytoplasmic region (amino acids 1-48) of both wild type and mutant NS4A in the presence of SDS micelles. Binding of the two N-terminal NS4A peptides to liposomes was studied as a function of membrane curvature and lipid composition. The NS4A N-terminal was found to contain two AHs separated by a non-helical linker. The above mentioned mutations did not significantly affect the helical secondary structure of this domain. However, they reduced the affinity of the N-terminal NS4A domain for lipid membranes. Binding of wild type NS4A(1-48) to liposomes is highly dependent on membrane curvature.
authors: Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany.
authors: Yu-Fu
authors: YF
authors: Hung
authors: Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany.
authors: Melanie
authors: M
authors: Schwarten
authors: Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany.
authors: Sven
authors: S
authors: Schünke
authors: Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany.
authors: Pallavi
authors: P
authors: Thiagarajan-Rosenkranz
authors: Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany.
authors: Silke
authors: S
authors: Hoffmann
authors: Department Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
authors: Ella H
authors: EH
authors: Sklan
authors: Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany.
authors: Dieter
authors: D
authors: Willbold
authors: Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany. Electronic address: b.koenig@fz-juelich.de.
authors: Bernd W
authors: BW
authors: Koenig
mesh_terms: D002942:Circular Dichroism; D003716:Dengue Virus / Q000254:growth & development / Q000378:metabolism*; D008081:Liposomes; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D008823:Micelles; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D020349:Surface Plasmon Resonance; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D008081:Liposomes; D008563:Membrane Lipids; D008823:Micelles; C000601110:NS4A protein, Dengue virus; D017361:Viral Nonstructural Proteins
keywords: Amphipathic helix; Curvature sensing; Dengue virus; NMR spectroscopy; Non-structural protein NS4A; Peptide membrane interaction