Translation of alfalfa mosaic virus RNA's in mammalian cell-free systems

Four alfalfa mosaic virus (AMV) RNA's have been isolated by electrophoresis on polyacrylamide gels and used as messengers in the in vitro protein-synthesizing systems prepared from rabbit reticulocyte lysates and Krebs-II ascites cells. These two systems have been shown to be capable of translating all of the RNA's. The translation product of the 12 S RNA has been found to be identical to the AMV coat protein by molecular weight estimation, serology and fingerprint analysis. The major product of 17 S RNA consists of a polypeptide of 35,000 daltons, which only represents a partial translation of this RNA. For 20 and 24 S RNA's, several specific polypeptides can be found in both cell-free systems. In contrast to the Krebs-II ascites cell system, the reticulocyte system, which is devoid of RNase activity, seems capable of producing polypeptides of high molecular weight. Moreover, in both systems, with the exception of 17 S RNA, a polypeptide corresponding to the translation of the whole length of the RNA can be found, thus suggesting a monocistronic messenger behavior for each of the three other RNA's.