Mutations that affect phosphorylation of the adenovirus DNA-binding protein alter its ability to enhance its own synthesis

The DNA-binding protein (DBP) encoded by the E2A region of adenovirus type 5 was found to enhance the expression of a reporter gene controlled by several different promoters within transfected cells. The rate of synthesis of correctly initiated transcripts was increased by the DBP. The adeno-associated virus P5 promoter and the adenovirus ElA and E2A early and major late promoters responded to the DBP by increases in expression ranging from 6to 27-fold, while the adenovirus E4 promoter was slightly inhibited by DBP. The adenovirus major late promoter showed a greater response to DBP than to the ElA transactivator protein, suggesting that the DBP plays a central role in activation of the late promoter. * Corresponding author. structed by using Bal 31 nuclease, and deletion endpoints were mapped by DNA sequencing. The rabbit P-globincoding region from pSV2-p-globin (52) was substituted for

Section: Discussionmentioning

confidence: 99%

The adenovirus DNA-binding protein stimulates the rate of transcription directed by adenovirus and adeno-associated virus promoters

Chang

Shenk

1990

“…2). In HAVs, the N-terminal domain is heavily phosphorylated at serine and threonine residues and contains most of the phosphates bound by the DBP molecule (43). The DBP of BAV-3 also contains a number of serine and threonine residues in the amino-terminal domain (Fig.…”

Section: Resultsmentioning

confidence: 99%

Nucleotide Sequence, Genome Organization, and Transcription Map of Bovine Adenovirus Type 3

Reddy

Idamakanti

Zakhartchouk

et al. 1998

The complete DNA sequence of bovine adenovirus type 3 is reported here. The size of the genome is 34,446 bp in length with a G+C content of 54%. All the genes of the early and late regions are present in the expected locations of the genome. However, the late-region genes are organized into seven families, instead of five as they are in human adenovirus type 2. The deduced amino acid sequences of open reading frames (ORFs) in the late regions and early region 2 (E2) and for IVa2 show higher degrees of homology, whereas the predicted amino acid sequences of ORFs in the E1, E3, and E4 regions and the pIX, fiber, and 33,000-molecular-weight nonstructural proteins show little or no homology with the corresponding proteins of other adenoviruses. In addition, the penton base protein lacks the integrin binding motif, RGD, but has an LDV motif instead of an MDV motif. Interestingly, as in other animal adenoviruses, the virus-associated RNA genes appear to be absent from their usual location. Sequence analysis of cDNA clones representing the early- and late-region genes identified splice acceptor and splice donor sites, polyadenylation signals and polyadenylation sites, and tripartite leader sequences.

“…Thus, AcNPV dnapol gene transcription is inhibited late during infection, by a mechanism involving a viral or virally induced product(s), but not through any direct interference with ORF-2 expression. Since both the activation and inhibition mechanisms are targeted to a relatively small area around the dnapol proximal promoter, we think such an inhibiting factor might act by inducing a subtle change(s) (25) in the IEl protein properties and then indirectly triggering dnapol transcription inhibition.…”

Section: Discussionmentioning

confidence: 99%

Temporal regulation of a complex and unconventional promoter by viral products

Ohresser

Morin

Cérutti

et al. 1994

Self Cite

The DNA polymerase (dnapol) gene ofAutographa californica nuclear polyhedrosis virus presents a complex promoter organization. It lacks the usual TATA box and start site, and its RNA accumulation initially increases and then decreases dramatically during infection. We investigated dnapol temporal regulation. Transiently expressed dnapol gene was transcribed at a low level from minor start sites. Coexpression with ieO and/or iel immediate-early genes dramatically enhanced dnapol transcription, specifically from a new start site. Moreover, the iel transactivation required little or no information in front of this nonconventional proximal promoter. We showed that IEO and IEl proteins were stably expressed during infection and that the dnapol mRNA level decrease was not a consequence of the disappearance of these proteins. The dnapol promoter region contains a putative overlapping open reading frame (ORF) in the opposite direction. We showed that ORF-2 was indeed highly expressed late, when the dnapol mRNA level decreased, and that during that time, dnapol mRNA stability was not significantly altered, excluding a destabilizing antisense effect. Additionally, we showed that the dnapol promoter was inhibited late but not early during the infection of cells transiently expressing constructs carrying either the intact or the altered ORF-2 promoter. Therefore, ORF-2 initiation of transcription and dnapol promoter inhibition are two coincidental nonrelated phenomena. Finally, we showed that both IEl transactivation and late inhibition occurred in the same limited region around the dnapol promoter.