Expression of Early Viral Gene Products in Adenovirus Type 12-infected and -transformed cells

Abstract

SUMMARYWe have analysed early viral gene products expressed in adenovirus type 12 (Adl2)-infected cells as well as in two Adl2-transformed hamster cell lines, and Adl2-induced rat tumour cell lines by cell-free translation of virus-specific RNA which was selected by hybridization to cloned restriction endonuclease fragments of virus DNA. Proteins synthesized in vitro were analysed by one-and twodimensional gel electrophoresis. It was found that RNA encoded by early region E1A directs the synthesis of at least eight polypeptides with apparent mol. wt. 38K, 36K, 30K, 28K, 26K, 25K, 24K and 22K. All these proteins are related to each other. E1B-specific RNA directs the synthesis of three proteins: 59K, 19K and 17K. Early region E2a codes for a 61K polypeptide which probably represents the single-strand DNA-binding protein of Adl2. RNA complementary to region E3 directs the synthesis of a 16K protein, and RNA transcribed from region E4 the synthesis of polypeptides with mol. wt. 20K, 18K and l l.5K. We have mapped a 67K polypeptide into the region within 11 to 28 map units (E2b). The analysis of proteins directed by virus-specific RNAs prepared from two Adl2-transformed hamster cell lines (T637, HA12/7) and one Adl2-induced rat tumour line (RBT12/3) showed that early regions E1 and E4 are expressed in all three Adl2-transformed cell lines. RNA transcribed from early regions E2 and E3 have been detected in lines T637 and RBT12/3. The virus RNA prepared from the Adl2-transformed cell lines directed synthesis of polypeptides with mol. wt. very similar to those of early virus proteins from infected cells. However, in all three Adl2-transformed cell lines mentioned above we have found RNAs which directed the synthesis of additional polypeptides of early regions E1 (34K) and E4 (25K, 24K) not detected in infected cells. The DNA sequence between 11 and 28 map units (coding for the 67K protein) is not expressed in the Ad 12-transformed cells.

Sequence, Transcription and Translation of a Late Gene of the Autographa californica Nuclear Polyhedrosis Virus Encoding a 34.8K Polypeptide

“…respectively) was heated at 100 °C for 2 rain, snap-cooled and absorbed onto a 1 cm 2 section of a nitrocellulose filter (Schleicher & Schuell). The filter was washed with 6 x SSC and then baked for 2 h at 80 °C in a vacuum (Esche & Siegmann, 1982;. Hybridization was conducted for 12 h at 42 °C in 50~ formamide, 10 raM-PIPES pH 6.4, 0-4 M-NaCI, 1 mM-EDTA with 3 mg of total RNA isolated from cells at 12 h after infection.…”

Acylation of adenovirus type 12 early region Ib 18‐kDa protein

“…Reasons for this discrepancy are not clear although it might be indicative of group differences between Ad 12 and Ad 5. However, a number of workers [9,23] fig.1, scans k, 1).…”

DNA Methylation--A Regulatory Signal in Eukaryotic Gene Expression

“…The most striking correlation in this respect has been found for the early region 2a (E2a) of Ad2 DNA in three cell lines of Ad2-transformed hamster cells. In line HE1, the 72K, DNA-binding protein (DBP) of Ad2 DNA is expressed, but in lines HE2 and HE3 this protein is not synthesized (Johansson et al, 1978;Esche, 1981). The 5'-CCGG-3' sites of the E2a region in line HE1 are completely unmethylated; in lines HE2 and HE3 the same sites are fully methylated.…”