The transmembrane domains of hepatitis C virus envelope glycoproteins E1 and E2 play a major role in heterodimerization.
Oligomerization of viral envelope proteins is essential to control virus assembly and fusion. The transmembrane domains (TMDs) of hepatitis C virus envelope glycoproteins E1 and E2 have been shown to play multiple functions during the biogenesis of E1E2 heterodimer. This makes them very unique among known transmembrane sequences. In this report, we used alanine scanning insertion mutagenesis in the TMDs of E1 and E2 to examine their role in the assembly of E1E2 heterodimer. Alanine insertion within the center of the TMDs of E1 or E2 or in the N-terminal part of the TMD of E1 dramatically reduced heterodimerization, demonstrating the essential role played by these domains in the assembly of hepatitis C virus envelope glycoproteins. To better understand the alanine scanning data obtained for the TMD of E1 which contains GXXXG motifs, we analyzed by circular dichroism and nuclear magnetic resonance the three-dimensional structure of the E1-(350-370) peptide encompassing the N-terminal sequence of the TMD of E1 involved in heterodimerization. Alanine scanning results and the three-dimensional molecular model we obtained provide the first framework for a molecular level understanding of the mechanism of hepatitis C virus envelope glycoprotein heterodimerization.
Op De Beeck
A
A
CNRS-UMR8526, IBL/Institut Pasteur de Lille, 59021 Lille Cedex, France, the CNRS-UMR 5086, IBCP, 69367 Lyon Cedex 07, France.
Montserret
R
R
Duvet
S
S
Cocquerel
L
L
Cacan
R
R
Barberot
B
B
Le Maire
M
M
Penin
F
F
Dubuisson
J
J
D000409:Alanine / Q000737:chemistry; D000595:Amino Acid Sequence; D015704:CD4 Antigens / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D019281:Dimerization; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009844:Oligosaccharides / Q000378:metabolism; D010455:Peptides / Q000138:chemical synthesis; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D013997:Time Factors; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000502:physiology
D015704:CD4 Antigens; C087035:E1 protein, Hepatitis C virus; D009844:Oligosaccharides; D010455:Peptides; D014759:Viral Envelope Proteins; C091015:glycoprotein E2, Hepatitis C virus; D000409:Alanine