Expression of the porcine transmissible gastroenteritis coronavirus M protein

Cloned cDNA encoding the M protein of the porcine transmissible gastroenteritis coronavirus (TGEV) was introduced into a vaccinia virus to examine the function of the amino-terminal signal peptide. The M protein expressed by the recombinant virus was targeted to the Golgi region of infected cells, as is the M protein in cells infected with TGEV. The protein appeared not to undergo processing other than glycosylation. However, the vaccinia-expressed M protein was slightly larger than the protein found in TGEV-infected cells, suggesting that a difference in modification exists between the proteins.