Transcription of minute virus of mice, an autonomous parvovirus, may be regulated by attenuation

Abstract

To characterize the transcriptional organization and regulation of minute virus of mice, an autonomous parvovirus, viral transcriptional complexes were isolated and cleaved with restriction enzymes. The in vivo preinitiated nascent RNA was elongated in vitro in the presence of [ot-32P]UTP to generate runoff transcripts. The lengths of the runoff transcripts were analyzed by gel electrophoresis under denaturing conditions. On the basis of the map locations of the restriction sites and the lengths of the runoff transcripts, the in vivo initiation sites were determined. Two major initiation sites having similar activities were thus identified at residues 201 ± 5 and 2005 ± 5; both of them were preceded by a TATAA sequence. When uncleaved viral transcriptional complexes or isolated nuclei were incubated in vitro in the presence of [a-32P]UTP or [0t-32P]CTP, they synthesized labeled RNA that, as determined by polyacrylamide gel electrophoresis, contained a major band of 142 nucleotides. The RNA of the major band was mapped between the initiation site at residue 201 ± 5 and residue 342. We noticed the potential of forming two mutually exclusive stem-and-loop structures in the 142nucleotide RNA; one of them is followed by a string of uridylic acid residues typical of a procaryotic transcription termination signal. We propose that, as in the transcription of simian virus 40, RNA transcription in minute virus of mice may be regulated by attenuation and may involve eucaryotic polymerase B, which can respond to a transcription termination signal similar to that of the procaryotic polymerase.

Positive and negative regulation of the minute virus of mice P38 promoter

“…The RNA start sites, which prior to this report had only been mapped to within 10 bp, were heterogeneous with the major start site at nt 2005 and two minor sites at nt 2006 and 2009. The major start site agrees with the initiation site predicted from both in vivo (8,10,11) and in vitro (4,20) data. In addition, very weakly labeled bands suggested some initiation at nt 2007 and 2008.…”

The adeno-associated virus (AAV) Rep protein acts as both a repressor and an activator to regulate AAV transcription during a productive infection

“…In the presence of Ad, when AAV undergoes a productive infection, a mechanism must exist for efficiently inducing the three promoters. The primary proteins used for control of AAV transcription are the products of the viral rep gene (3,6,18,32). In this report, we have focused on the role of the AAV Rep proteins and the cis active elements in the p5 promoter in controlling AAV transcription during a productive infection.…”

Negative regulation of retrovirus expression in embryonal carcinoma cells mediated by an intragenic domain

“…Alternatively, elongation could be blocked by interaction at the RNA level by an attenuationlike mechanism. It has been proposed that attenuation is involved in the regulation of several eucaryotic virus life cycles (4,16,19,27). Although the persistence of inhibition following inversion of the inhibitory component (Fig.…”