Processing of a pseudorabies virus-induced protein which is glycosylated, sulphated and excreted.

Cells infected with pseudorabies virus excrete large amounts of a glycosylated sulphated protein, mol. wt. 89000, into the extracellular fluid. This paper reports the results of studies on the processing of this protein. Glycosylation occurs during, or very soon after, synthesis of the polypeptide chain. After a delay of several minutes the glycoprotein is sulphated; inhibition of glycosylation by high concentrations of glucosamine does not interfere with this process. The glycosylated sulphated polypeptide is then reduced in size from mol. wt. 99000 to 89000, possibly by proteolytic cleavage, and is excreted. Inhibition of glycosylation does not interfere with the excretion of this polypeptide, which is an energy-requiring process.