Dissection of Semliki Forest virus glycoprotein delivery from the trans-Golgi network to the cell surface in permeabilized BHK cells.

In this paper mechanically permeabilized cells have been used to dissect the transport of Semliki Forest virus glycoproteins from the trans-Golgi network to the plasma membrane. Transport from the Golgi complex was monitored by measuring the proteolytic cleavage of the Semliki Forest virus p62 glycoprotein into the E2 and E3 polypeptide chains. Cell surface appearance was measured by the exposure of the exoplasmic domain to antibodies directed against the viral glycoprotein. Both the cleavage of the p62 protein and the transport of the glycoprotein to the cell surface were reconstituted in permeabilized BHK cells when calcium and glucose were present in the medium. Detailed analysis showed that the cleavage of the p62 protein occurred before arrival to the plasma membrane.