Dengue virus type 1 nonstructural glycoprotein NS1 is secreted from mammalian cells as a soluble hexamer in a glycosylation-dependent fashion.
Nonstructural glycoprotein NS1, specified by dengue virus type 1 (Den-1), is secreted from infected green monkey kidney (Vero) cells in a major soluble form characterized by biochemical and biophysical means as a unique hexameric species. This noncovalently bound oligomer is formed by three dimeric subunits and has a molecular mass of 310 kDa and a Stokes radius of 64.4 A. During protein export, one of the two oligosaccharides of NS1 is processed into an endo-beta-N-acetylglucosaminidase F-resistant complex-type sugar while the other remains of the polymannose type, protected in the dimeric subunit from the action of maturation enzymes. Complete processing of the complex-type sugar appears to be required for efficient release of soluble NS1 into the culture fluid of infected cells, as suggested by the repressive effects of the N-glycan processing inhibitors swainsonine and deoxymannojyrimicin. These results, together with observations related to the absence of secretion of NS1 from Den-infected insect cells, suggest that maturation and secretion of hexameric NS1 depend on the glycosylation status of the host cell.
Flamand
M
M
Unité des Arbovirus et Virus des Fièvres Hémorragiques, Institut Pasteur, 75724 Paris Cedex 15, 91198 Gif-sur-Yvette Cedex, France. mflamand@pasteur.fr
Megret
F
F
Mathieu
M
M
Lepault
J
J
Rey
F A
FA
Deubel
V
V
D000818:Animals; D002241:Carbohydrates / Q000096:biosynthesis; D002522:Chlorocebus aethiops; D003716:Dengue Virus / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D008322:Mammals; D011487:Protein Conformation; D012995:Solubility; D014709:Vero Cells; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
D002241:Carbohydrates; C082515:NS1 protein, dengue-1 virus; D017361:Viral Nonstructural Proteins