Adenovirus type 2 early proteins synthesized in vitro and in vivo: identification in infected cells of the 38,000- to 50,000- molecular-weight protein encoded by the left end of the adenovirus type 2 genome

Abstract

Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of protein synthesized early after infection of human [cervical carcinoma HeLa] cells with adenovirus type 2 (Ad2) showed that polypeptides of 11,000 (11K), 12K, 14K, 15K, 19K, 21K, 24K and 72K MW were present in infected but not in mock-infected cells. These polypeptides corresponded in electrophoretic mobility to the following polypeptides synthesized in vitro by using mRNA complementary to specific regions of the Ad2 genome: 11K, 19K, 21K (91.5-96.8 map units), 14K (78.2-83.4 map units), 72K (62.4-67.9 map units) and 15K (4.9-11.0 map units). Polypeptides of 25K, 17K, 15.5K and 13K were also synthesized in vitro, but were not yet detected in infected cells. Six adeno-specific polypeptides of 38-50K MW could also be discerned in infected cells if 2-dimensional isoelectric focusing-polyacrylamide gel electrophoresis was used to compare extracts from infected and mock-infected cells. Partial protease digestion showed these 38-50K polypeptides to be related in sequence to each other and to the 40-50K polypeptide made in vitro (1.3-4.0 map units).