High-resolution footprints of the DNA-binding domain of Epstein-Barr virus nuclear antigen 1

1989 ◽  
Vol 9 (6) ◽  
pp. 2738-2742
Author(s):  
A S Kimball ◽  
G Milman ◽  
T D Tullius

The DNA-binding domain of Epstein-Barr virus nuclear antigen 1 was found by hydroxyl radical footprinting to protect backbone positions on one side of its DNA-binding site. The guanines contacted in the major groove by the DNA-binding domain of Epstein-Barr virus nuclear antigen 1 were identified by methylation protection. No difference was found in the interaction of the DNA-binding domain of Epstein-Barr virus nuclear antigen 1 with tandemly repeated and overlapping binding sites.

1989 ◽  
Vol 9 (6) ◽  
pp. 2738-2742 ◽  
Author(s):  
A S Kimball ◽  
G Milman ◽  
T D Tullius

The DNA-binding domain of Epstein-Barr virus nuclear antigen 1 was found by hydroxyl radical footprinting to protect backbone positions on one side of its DNA-binding site. The guanines contacted in the major groove by the DNA-binding domain of Epstein-Barr virus nuclear antigen 1 were identified by methylation protection. No difference was found in the interaction of the DNA-binding domain of Epstein-Barr virus nuclear antigen 1 with tandemly repeated and overlapping binding sites.


2013 ◽  
Vol 87 (23) ◽  
pp. 13020-13028 ◽  
Author(s):  
Theresa L. Hodin ◽  
Tanbir Najrana ◽  
John L. Yates

The EBNA1 protein of Epstein-Barr virus enables plasmids carryingoriPboth to duplicate and to segregate efficiently in proliferating cells. EBNA1 recruits the origin recognition complex (ORC) to establish a replication origin at one element oforiP, DS (dyadsymmetry); at another element, FR (family ofrepeats), EBNA1 binds to an array of sites from which it tethers plasmids to host chromosomes for mitotic stability. We report experiments leading to the conclusion that tethering by EBNA1 to host chromosomes is also needed within interphase nuclei in order for plasmids to be replicated efficiently fromoriP. The DNA-binding domain of EBNA1, which lacks chromosome-binding ability, was found to support weak, DS-specific replication in HEK293 cells after transient transfection, being 17% as active as wild-type EBNA1. The low efficiency of replication was not due to the failure of the DNA-binding domain to retain plasmids within nuclei, because plasmids were recovered in similar amounts and entirely from the nuclear fraction of these transiently transfected cells. A derivative of EBNA1 with its chromosome-tethering domains replaced by a 22-amino-acid nucleosome-binding domain was fully active in supportingoriPfunctions. The implication is that EBNA1's DNA-binding domain is able to recruit ORC to DS, but either this step or subsequent replication is only efficient if the plasmid is tethered to a host chromosome. Finally, with some cell lines, DS can hardly support even transient plasmid replication without FR. A loss of plasmids lacking FR from nuclei cannot account for this requirement, suggesting that the stronger tethering to chromosomes by FR is needed for plasmid replication within the nuclei of such cells.


Cell ◽  
1996 ◽  
Vol 84 (5) ◽  
pp. 791-800 ◽  
Author(s):  
Alexey Bochkarev ◽  
Jean A Barwell ◽  
Richard A Pfuetzner ◽  
Elena Bochkareva ◽  
Lori Frappier ◽  
...  

Cell ◽  
1995 ◽  
Vol 83 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Alexey Bochkarev ◽  
Jean A. Barwell ◽  
Richard A. Pfuetzner ◽  
William Furey ◽  
Aled M. Edwards ◽  
...  

1996 ◽  
Vol 77 (5) ◽  
pp. 991-996 ◽  
Author(s):  
C. Sauder ◽  
N. Gotzinger ◽  
W. H. Schubach ◽  
G. C. Horvath ◽  
E. Kremmer ◽  
...  

1995 ◽  
Vol 270 (35) ◽  
pp. 20556-20559 ◽  
Author(s):  
Jean A. Barwell ◽  
Alexey Bochkarev ◽  
Richard A. Pfuetzner ◽  
Harry Tong ◽  
Daniel S. C. Yang ◽  
...  

2000 ◽  
Vol 74 (11) ◽  
pp. 5151-5160 ◽  
Author(s):  
Bo Zhao ◽  
Clare E. Sample

ABSTRACT The Epstein-Barr virus (EBV) nuclear antigen 3C (EBNA-3C) protein is a transcriptional regulator of viral and cellular genes that is essential for EBV-mediated immortalization of B lymphocytes in vitro. EBNA-3C can inhibit transcription through an association with the cellular DNA-binding protein Jκ, a function shared by EBNA-3A and EBNA-3B. Here, we report a mechanism by which EBNA-3C can activate transcription from the EBV latent membrane protein 1 (LMP-1) promoter in conjunction with EBNA-2. Jκ DNA-binding sites were not required for this activation, and a mutant EBNA-3C protein unable to bind Jκ activated transcription as efficiently as wild-type EBNA-3C, indicating that EBNA-3C can regulate transcription through a mechanism that is independent of Jκ. Furthermore, activation of the LMP-1 promoter is a unique function of EBNA-3C, not shared by EBNA-3A and EBNA-3B. The DNA element through which EBNA-3C activates the LMP-1 promoter includes a Spi-1/Spi-B binding site, previously characterized as an important EBNA-2 response element. Although this element has considerable homology to mouse immunoglobulin light chain promoter sequences to which the mouse homologue of Spi-1 binds with its dimerization partner IRF4, we demonstrate that the IRF4-like binding sites in the LMP-1 promoter do not play a role in EBNA-3C-mediated activation. Both EBNA-2 and EBNA-3C were required for transcription mediated through a 41-bp region of the LMP-1 promoter encompassing the Spi binding site. However, EBNA-3C had no effect on transcription mediated in conjunction with the EBNA-2 activation domain fused to the GAL4 DNA-binding domain, suggesting that it does not function as an adapter between EBNA-2 and the cellular transcriptional machinery. Like EBNA-2, EBNA-3C bound directly to both Spi-1 and Spi-B in vitro. This interaction was mediated by a region of EBNA-3C encompassing a likely basic leucine zipper (bZIP) domain and the ets domain of Spi-1 or Spi-B, reminiscent of interactions between bZIP and ets domains of other transcription factors that result in their targeting to DNA. There are many examples of regulation of the hematopoietic-specific Spi transcription factors through protein-protein interactions, and a similar regulation by EBNA-3C, in conjunction with EBNA-2, is likely to be an important and unique contribution of EBNA-3C to EBV-mediated immortalization.


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