Identification of an ovine atadenovirus gene whose product activates the viral E2 promoter: possible involvement of E2F-1

Item Type:	Article
Title:	Identification of an ovine atadenovirus gene whose product activates the viral E2 promoter: possible involvement of E2F-1
Creators Name:	Kuemin, D. and Hofmann, C. and Uckert, W. and Both, G.W. and Loeser, P.
Abstract:	Activation of the adenoviral E2 promoter is an early step in adenovirus gene expression. For members of the mast- and aviadenoviruses, this requires induction of the cellular transcription factor E2F by virally encoded gene products such as E1A, E4orf6/7 and orf22/GAM-1. The newly recognized genus atadenovirus, of which the ovine isolate OAdV is the prototype, lacks any sequence homology to those genes. To find a possible link between E2 promoter activation and OAdV gene expression, we utilized a screening method to search for genes within the OAdV genome that were capable of stimulating the viral E2 promoter. One such gene, E43, was identified within the proposed E4 region toward the right-hand end of the OAdV genome. The E43 gene product was also found to be capable of stimulating E2F-1-dependent gene expression. A closer inspection of the E2 promoter revealed the presence of a non-palindromic E2F binding site within the OAdV E2 promoter. Mutation of this site markedly reduced both E2F-1- and E43-dependent promoter activation. Moreover, a direct protein–protein interaction of the E43 gene product with E2F, but not with the retinoblastoma protein pRb, suggested a possible cooperation between these two proteins in activating the E2 promoter. The importance of the E43 gene product for virus replication is also underlined by the finding that an OAdV recombinant with a functionally inactivated E43 gene showed severely inhibited virus growth.
Keywords:	Ovine Atadenovirus, E2F, E2 Promoter, E43 Protein, Retinoblastoma Protein, Animals, Sheep
Source:	Virology
ISSN:	0042-6822
Publisher:	Academic Press
Volume:	318
Number:	1
Page Range:	79-89
Date:	5 January 2004
Official Publication:	https://doi.org/10.1016/j.virol.2003.09.002
PubMed:	View item in PubMed

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