Intracellular synthesis of measles virus-specified polypeptides

Abstract

The intracellular synthesis of measles-specified polypeptides was examined by polyacrylamide gel electrophoresis of [African green monkey kidney CV-1] cell extracts. Since measles virus does not efficiently shut off host-cell protein synthesis, high multiplicities of infection were used to enable viral polypeptides to be detected against the high background of cellular protein synthesis. The cytoplasm of infected cells contained viral structural polypeptides with estimated MW of 200,000, 80,000, 70,000, 60,000, 41,000 and 37,000. All of these structural polypeptides, with the exception of P1, the only virion glycoprotein (MW .simeq. 80,000), were also found in the nuclei. Two nonstructural polypeptides with estimated MW of 74,000 and 72,000 were also present in the cytoplasm of infected cells. The initial synthesis of the smaller, nonstructural polypeptide began later in infection than the structural polypeptides. Pulse-chase experiments failed to detect any precursor-product relationships. The intracellular glycosylation and phosphorylation of the viral polypeptides were similar to those found in purified virions.