TY - JOUR
T1 - The polypeptides of influenza virus. VII. Synthesis of the hemagglutinin
AU - Stanley, Pamela
AU - Gandhi, S. S.
AU - White, D. O.
N1 - Funding Information:
The glycoprotein of molecular weight (MW) 75,000-79,000 which comprises the hemagglutinin of influenza virus can sometimes be dissociated, under reducing conditions, to yield two distinct glycoproteins of MW 50,000-65,000 and 21,00030,000 (Has-lam et al ., 1970a, b ; Laver, 1971 ; Lazarowitz et al ., 1971 ; Skehel and Schild, 1971 ; Stanley and Haslam, 1971) . These glycoproteins are designated HA, HA I , and HA2, respectively 1 Supported by the Australian Research Grants Committee . % Present address : Department of Medical Cell Biology, University of Toronto, Ontario, Canada . Present Address : National Biological Standards Laboratory, Viral Products Section, Parkville, Victoria 3052, Australia .
PY - 1973/5
Y1 - 1973/5
N2 - Post-translational cleavage of the influenza viral glycoprotein HA occurs to different extents in different systems, varying not only for a particular virus strain grown in different host cells, but also for two strains of virus grown in the same host cell. Preparations of virus in which the HA is not substantially cleaved contain hemagglutinating and infectious virions. Cleavage occurs at different sites in the HA molecule of different virus strains. The hemagglutinin glycoprotein HA is always found in association with cytoplasmic membranes and becomes rapidly incorporated into plasma membranes. Following a 10-min pulse-label, there is already about half as much HA in preparations of plasma membranes as eventually accumulates there during a 90-min chase. Membrane preparations which appear to be mainly composed of smooth endoplasmic reticulum are greatly enriched for HA while plasma membranes contain HA and the other major viral proteins. At 24 hr after infection, the amount of HA or its cleavage products in BHK21 cells infected with Bel or WSN represents a much smaller proportion of the total viral protein than the proportion of HA in purified virions. The same is true for the membrane protein, M, whereas NP is present in excess in the infected cell. Inhibition of protein synthesis by puromycin stops the incorporation of glucosamine into Bel-infected HeLa cells almost immediately, suggesting that glycosylation of HA occurs quickly. However, fucose continues to be incorporated for apporoximately 10-15 min after protein synthesis has been blocked by puromycin or after glycosiliation has been inhibited by glucosamine hydrochloride.
AB - Post-translational cleavage of the influenza viral glycoprotein HA occurs to different extents in different systems, varying not only for a particular virus strain grown in different host cells, but also for two strains of virus grown in the same host cell. Preparations of virus in which the HA is not substantially cleaved contain hemagglutinating and infectious virions. Cleavage occurs at different sites in the HA molecule of different virus strains. The hemagglutinin glycoprotein HA is always found in association with cytoplasmic membranes and becomes rapidly incorporated into plasma membranes. Following a 10-min pulse-label, there is already about half as much HA in preparations of plasma membranes as eventually accumulates there during a 90-min chase. Membrane preparations which appear to be mainly composed of smooth endoplasmic reticulum are greatly enriched for HA while plasma membranes contain HA and the other major viral proteins. At 24 hr after infection, the amount of HA or its cleavage products in BHK21 cells infected with Bel or WSN represents a much smaller proportion of the total viral protein than the proportion of HA in purified virions. The same is true for the membrane protein, M, whereas NP is present in excess in the infected cell. Inhibition of protein synthesis by puromycin stops the incorporation of glucosamine into Bel-infected HeLa cells almost immediately, suggesting that glycosylation of HA occurs quickly. However, fucose continues to be incorporated for apporoximately 10-15 min after protein synthesis has been blocked by puromycin or after glycosiliation has been inhibited by glucosamine hydrochloride.
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U2 - 10.1016/0042-6822(73)90468-6
DO - 10.1016/0042-6822(73)90468-6
M3 - Article
C2 - 4735937
AN - SCOPUS:0015878494
SN - 0042-6822
VL - 53
SP - 92
EP - 106
JO - Virology
JF - Virology
IS - 1
ER -