scholarly journals Comparative Sequence Analysis of the Largest E1A Proteins of Human and Simian Adenoviruses

2002 ◽  
Vol 76 (16) ◽  
pp. 7968-7975 ◽  
Author(s):  
Nikita Avvakumov ◽  
Russ Wheeler ◽  
Jean Claude D'Halluin ◽  
Joe S. Mymryk

ABSTRACT The early region 1A (E1A) gene is the first gene expressed after infection with adenovirus and has been most extensively characterized in human adenovirus type 5 (hAd5). The E1A proteins interact with numerous cellular regulatory proteins, influencing a variety of transcriptional and cell cycle events. For this reason, these multifunctional proteins have been useful as tools for dissecting pathways regulating cell growth and gene expression. Despite the large number of studies using hAd5 E1A, relatively little is known about the function of the E1A proteins of other adenoviruses. In 1985, a comparison of E1A sequences from three human and one simian adenovirus identified three regions with higher overall levels of sequence conservation designated conserved regions (CR) 1, 2, and 3. As expected, these regions are critical for a variety of E1A functions. Since that time, the sequences of several other human and simian adenovirus E1A proteins have been determined. Using these, and two additional sequences that we determined, we report here a detailed comparison of the sequences of 15 E1A proteins representing each of the six hAd subgroups and several simian adenoviruses. These analyses refine the positioning of CR1, 2, and 3; define a fourth CR located near the carboxyl terminus of E1A; and suggest several new functions for E1A.

2013 ◽  
Vol 41 (6) ◽  
pp. 3532-3550 ◽  
Author(s):  
Sabrina Schreiner ◽  
Carolin Bürck ◽  
Mandy Glass ◽  
Peter Groitl ◽  
Peter Wimmer ◽  
...  

2015 ◽  
Vol 89 (14) ◽  
pp. 7053-7063 ◽  
Author(s):  
Jordan Wright ◽  
Zeenah Atwan ◽  
Susan J. Morris ◽  
Keith N. Leppard

ABSTRACTThe late phase of adenovirus gene expression is controlled by proteins made in the intermediate phase, including L4 proteins of 22,000- and 33,000-Da apparent molecular mass (L4-22K and -33K proteins) that are expressed initially from the L4 promoter (L4P). The L4P is activated by a combination of viral proteins and cellular p53 and is ultimately inhibited again by its own products. Here, we have examined the L4P of human adenovirus type 5 in detail and have defined its transcription start site, which our data suggest is positioned by a weak TATA box. Rather than contributing positively to promoter activity, a putative initiator element at the transcription start site acts as a target for negative regulation imposed on the L4P by cellular TFII-I. We show that this TFII-I inhibition is relieved by one of the previously defined viral activators of the L4P, the E4 Orf3 protein, which alters the pool of TFII-I in the cell. We also explore further the negative regulation of the L4P by its products and show that the L4-33K protein is more significant in this process than L4-22K. It is the combined actions of positive and negative factors that lead to the transient activation of the L4P at the onset of the late phase of adenovirus gene expression.IMPORTANCEThe adenovirus replication cycle proceeds through multiple phases of gene expression in which a key step is the activation of late-phase gene expression to produce proteins from which progeny particles can be formed. Working with human adenovirus type 5, we showed previously that two proteins expressed from the L4 region of the viral genome perform essential roles in moving the infection on into the late phase; these two proteins are produced by the action of a dedicated promoter, the L4P, and without them the infection does not proceed successfully to progeny generation. In this new work, we delineate further aspects of L4P activity and regulation. Understanding how the L4P works, and how it contributes to activation of the late phase of infection, is important to our understanding of natural infections by the virus, in which late gene expression can fail to occur, allowing the virus to persist.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1483
Author(s):  
Emily A. Bates ◽  
John R. Counsell ◽  
Sophie Alizert ◽  
Alexander T. Baker ◽  
Natalie Suff ◽  
...  

The human adenovirus phylogenetic tree is split across seven species (A–G). Species D adenoviruses offer potential advantages for gene therapy applications, with low rates of pre-existing immunity detected across screened populations. However, many aspects of the basic virology of species D—such as their cellular tropism, receptor usage, and in vivo biodistribution profile—remain unknown. Here, we have characterized human adenovirus type 49 (HAdV-D49)—a relatively understudied species D member. We report that HAdV-D49 does not appear to use a single pathway to gain cell entry, but appears able to interact with various surface molecules for entry. As such, HAdV-D49 can transduce a broad range of cell types in vitro, with variable engagement of blood coagulation FX. Interestingly, when comparing in vivo biodistribution to adenovirus type 5, HAdV-D49 vectors show reduced liver targeting, whilst maintaining transduction of lung and spleen. Overall, this presents HAdV-D49 as a robust viral vector platform for ex vivo manipulation of human cells, and for in vivo applications where the therapeutic goal is to target the lung or gain access to immune cells in the spleen, whilst avoiding liver interactions, such as intravascular vaccine applications.


2002 ◽  
Vol 50 (4) ◽  
pp. 481-489 ◽  
Author(s):  
Cs. Jeney ◽  
Boglárka Banizs ◽  
Orsolya Dobay ◽  

The effects of bafilomycin A1 and of the reduced level of endosomal epsilon-COP (coatomer protein) on the infectivity of human adenovirus type 5 were investigated in Coxsackie adenovirus receptor- (CAR-) transfected Chinese hamster ovary (CHO) cells. The endosomal proton pump inhibitor bafilomycin A1 was able to cause only partial inhibition. Using ldlF cells (an epsilon-COP thermosensitive mutant CHO cell line) the reduction of epsilon-COP level also had partial inhibitory effect. Based on these results and comparing them to existing models of the adenovirus entry, we propose a refined model in which there are two pathways of adenoviral entry: the first one involves the epsilon-COP as the downstream effector of the acidification and can be blocked by bafilomycin A1 and the second one is a pH-independent pathway.


2002 ◽  
Vol 83 (1) ◽  
pp. 151-155 ◽  
Author(s):  
Christopher J. Cohen ◽  
Zhi Quan Xiang ◽  
Guang-Ping Gao ◽  
Hildegund C. J. Ertl ◽  
James M. Wilson ◽  
...  

A replication-defective form of chimpanzee adenovirus type 68 (C68) has been developed to circumvent problems posed by widespread preexisting immunity to common human adenovirus vectors. To investigate the determinants of C68 tropism, its interaction with the coxsackievirus and adenovirus receptor (CAR) was studied. Although CHO cells were resistant to transduction by C68 as well as by adenovirus type 5 (Ad5), CHO cells expressing either human or murine CAR were transduced readily. C68 transduction, like Ad5 transduction, was blocked when cells were exposed to anti-CAR antibody or when virus was exposed to a soluble form of the CAR extracellular domain. These results indicate that gene delivery by C68 occurs by a CAR-dependent mechanism.


2004 ◽  
Vol 35 (6) ◽  
pp. 715-721 ◽  
Author(s):  
Sacha Gogev ◽  
Jean-Pierre Georgin ◽  
Fr�d�ric Schynts ◽  
Alain Vanderplasschen ◽  
Etienne Thiry

1988 ◽  
Vol 8 (9) ◽  
pp. 3955-3959 ◽  
Author(s):  
C Egan ◽  
T N Jelsma ◽  
J A Howe ◽  
S T Bayley ◽  
B Ferguson ◽  
...  

The binding sites for the 300-, 107-, and 105-kilodalton cellular proteins which associate with human adenovirus type 5 E1A products were studied with E1A deletion mutants. All appeared to bind to the amino-terminal half of E1A products in regions necessary for oncogenic transformation. These results suggest that these cellular species may be important for the biological activity of E1A products.


Gene ◽  
1988 ◽  
Vol 69 (1) ◽  
pp. 153-157 ◽  
Author(s):  
Rita Neumann ◽  
Jadwiga Chroboczek ◽  
Bernard Jacrot

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