Characterization of the polypeptides synthesized in cells infected with a temperature-sensitive mutant derived from an HVJ (Sendai virus) carrier culture.

The intracellular synthesis of virus-specific polypeptides in cells infected with the wild-type virus of HVJ (HVJ-W) (haemagglutinating virus of Japan--the Sendai strain of parainfluenza 1 virus) and with a temperature-sensitive (ts) mutant (HVJ-pB) derived from an HVJ carrier culture has been analysed by polyacrylamide gel electrophoresis. At the permissive temperature (32 degrees C), all of the known virus structural polypeptides were identified in cells infected with each strain of virus and in addition to the non-structural polypeptides B and C, another polypeptide at the region with a molecular weight of 26,000 to 27,000 (26 to 27K) could be detected in infected cells. At the non-permissive temperature (38 degrees C), the synthesis of the polypeptide M was markedly restrained in cells infected with HVJ-pB, while other major virus polypeptides were present in approximately comparable amounts to cells infected with the wild-type virus. A non-structural polypeptide with a molecular weight of 105K was dominant in ts mutant infected cells at higher temperatures and disappeared after temperature-shift from 38 degrees to 32 degrees C. The production of the non-structural polypeptides B and 27K was also temperature-sensitive. The molecular weights of the polypeptides B, M and 27K in HVJ-pB infected cells were larger than those of the corresponding polypeptides in HVJ-W infected cells. The synthesis of the M protein in HVJ-prinfected cells started just after lowering the incubation temperature and the newly made M protein was successfully incorporated into virus particles.