Inhibition of Glycosylation of the Influenza Virus Hemagglutinin

AUTOR(ES)

Schwarz, Ralph T.

RESUMO

d-Glucosamine and 2-deoxy-d-glucose interfere with the biosynthesis of the hemagglutinin glycoproteins. With increasing inhibitor concentrations a progressive decrease in size of the precursor HA and the cleavage products, HA1 and HA2 can be observed. The shift in molecular weight is paralleled by a decrease of the carbohydrate content. This was shown by labeling studies with radioactive sugars which revealed that the inhibitors block the incorporation into glycoproteins, whereas they have no or only slight effects on the uptake and activation of sugars. Under conditions of maximal inhibition, the hemagglutinin proteins lack all or most of their carbohydrates. These findings indicate that the inhibitory effect of d-glucosamine and 2-deoxy-d-glucose is due to an impairment of glycosylation. When glycosylation is inhibited, the precursor polypeptide is synthesized at normal rates. Its cleavage products, however, are very heterogeneous. This suggests that carbohydrate protects the hemagglutinin from proteolytic degradation.

Documentos Relacionados

• Glycosylation requirements for intracellular transport and function of the hemagglutinin of influenza virus.
• bcl-2 alters influenza virus yield, spread, and hemagglutinin glycosylation.
• Role of conserved glycosylation sites in maturation and transport of influenza A virus hemagglutinin.
• Glycosylation affects cleavage of an H5N2 influenza virus hemagglutinin and regulates virulence.
• Interdependence of Hemagglutinin Glycosylation and Neuraminidase as Regulators of Influenza Virus Growth: a Study by Reverse Genetics