Synthesis and processing of a gp28/32 membrane glycoprotein induced by Marek's disease virus serotype 2

The post-translational events leading from the precursor to the processed forms of a glycoprotein with an Mr of 28K to 32K (gp27/32) of Marek's disease virus (MDV) serotype 2 were examined with pulse-chase experiments and treatment with tunicamycin and monensin. Cell-free translation of infected cell mRNA followed by immunoprecipitation analysis suggested that a polypeptide with a size of 22K is the initial precursor. Experiments with endo-beta-N-acetylglucosaminidase H and endo-beta-N-acetylglucosaminidase F indicated that gp28/32 contains mostly N-linked oligosaccharides of the complex type. These studies showed that 22K, the initial product, is then processed through intermediates to the 28K to 32K form.