Glycoprotein synthesis in cells infected with vaccinia virus

When vaccinia-virus infected HeLa cells were incubated in medium containing radioactively labeled glucosamine, the specific activity of the UDP- N -acetylhexosamine pool increased linearly at a rate similar to that of uninfected cells, but starting at 2 hr after infection, hexosamines were incorporated into glycoproteins at a progressively lower rate.

Abstract

When vaccinia-virus infected HeLa cells were incubated in medium containing radioactively labeled glucosamine, the specific activity of the UDP-N-acetylhexosamine pool increased linearly at a rate similar to that of uninfected cells. Nevertheless, starting at 2 hr after infection, hexosamines were incorporated into glycoproteins at a progressively lower rate. Furthermore, from electrophoretic analysis it appeared as though synthesis of the major glycoproteins of uninfected cells was arrested and new glycoproteins were labeled. After equilibrium centrifugation the major vaccinia-induced glycoproteins did not sediment with infectious virus but a large portion was recovered from fractions rich in cell membranes and containing particulate material. Glycoproteins of similar electrophoretic mobilities were made in vaccinia-infected HeLa and chick cells. Both actinomycin D and cycloheximide inhibited the labeling of all virus-induced glycoproteins whereas rifamycin derivatives had a selective effect.