Differential inhibition of epstein-barr virus induction by the amino acid analogue, L-canavanine

1980 ◽  
Vol 25 (4) ◽  
pp. 439-443 ◽  
Author(s):  
Naoki Yamamoto ◽  
Nikolaus Mueller-Lantzsch ◽  
Harald Zur Hausen
Keyword(s):  
Amino Acid ◽  
Epstein Barr Virus ◽  
Amino Acid Analogue ◽  
Differential Inhibition ◽  
Barr Virus ◽  
Acid Analogue ◽  
Epstein Barr

scholarly journals Truncated mammalian Notch1 activates CBF1/RBPJk-repressed genes by a mechanism resembling that of Epstein-Barr virus EBNA2.

1996 ◽  
Vol 16 (3) ◽  
pp. 952-959 ◽  
Author(s):  
J J Hsieh ◽  
T Henkel ◽  
P Salmon ◽  
E Robey ◽  
M G Peterson ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Fate ◽  
Transcriptional Repression ◽  
Epstein Barr Virus ◽  
Cell Fate Decisions ◽  
Barr Virus ◽  
Amino Acid Region ◽  
Nuclear Events ◽  
Epstein Barr

The Notch/Lin-12/Glp-1 receptor family participates in cell-cell signaling events that influence cell fate decisions. Although several Notch homologs and receptor ligands have been identified, the nuclear events involved in this pathway remain incompletely understood. A truncated form of Notch, consisting only of the intracellular domain (NotchIC), localizes to the nucleus and functions as an activated receptor. Using both an in vitro binding assay and a cotransfection assay based on the two-hybrid principle, we show that mammalian NotchIC interacts with the transcriptional repressor CBF1, which is the human homolog of Drosophila Suppressor of Hairless. Cotransfection assays using segments of mouse NotchIC and CBF1 demonstrated that the N-terminal 114-amino-acid region of mouse NotchIC contains the CBF1 interactive domain and that the cdc10/ankyrin repeats are not essential for this interaction. This result was confirmed in immunoprecipation assays in which the N-terminal 114-amino-acid segment of NotchIC, but not the ankyrin repeat region, coprecipitated with CBF1. Mouse NotchIC itself is targeted to the transcriptional repression domain (aa179 to 361) of CBF1. Furthermore, transfection assays in which mouse NotchIC was targeted through Gal4-CBF1 or through endogenous cellular CBF1 indicated that NotchIC transactivates gene expression via CBF1 tethering to DNA. Transactivation by NotchIC occurs partially through abolition of CBF1-mediated repession. This same mechanism is used by Epstein-Barr virus EBNA2. Thus, mimicry of Notch signal transduction is involved in Epstein-Barr virus-driven immortalization.

scholarly journals Conserved Region CR2 of Epstein-Barr Virus Nuclear Antigen Leader Protein Is a Multifunctional Domain That Mediates Self-Association as well as Nuclear Localization and Nuclear Matrix Association

2002 ◽  
Vol 76 (3) ◽  
pp. 1025-1032 ◽  
Author(s):  
Michiko Tanaka ◽  
Akihiko Yokoyama ◽  
Mie Igarashi ◽  
Go Matsuda ◽  
Kentaro Kato ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nuclear Localization ◽  
Nuclear Matrix ◽  
Epstein Barr Virus ◽  
Cellular Proteins ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Leader Protein ◽  
Epstein Barr ◽  
Self Association

ABSTRACT Self-association of viral proteins is important for many of their functions, including enzymatic, transcriptional, and transformational activities. Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) contains various numbers of W1W2 repeats and a unique carboxyl-terminal Y1Y2 domain. It was reported that EBNA-LP associates with a variety of cellular proteins and plays a critical role in EBV-induced transformation. We report here that EBNA-LP self-associates in vivo and the domain responsible for the homotypic association is a multifunctional domain mediating nuclear localization, nuclear matrix association, and EBNA-2-dependent coactivator function of the protein. Our conclusions are based on the following observations. (i) EBNA-LP interacts with itself or its derivatives in the yeast two-hybrid system. (ii) A purified chimeric protein consisting of glutathione S-transferase fused to EBNA-LP specifically formed complexes with EBNA-LP transiently expressed in COS-7 cells. (iii) When Flag epitope-tagged EBNA-LP with either one or two W1W2 repeats and EBNA-LP containing four W1W2 repeats were coexpressed in COS-7 cells, the latter was specifically coimmunoprecipitated with the former. (iv) Mutational analyses of EBNA-LP with deletion mutants revealed that the region between codons 19 and 39 (relative to the first amino acid residue of the W2 domain) is essential for self-association of the protein. The mapped region almost completely overlaps with CR2 and CR3, regions conserved among a subset of primate γ-herpesviruses and critical for EBNA-2-dependent coactivator function. Amino acid substitutions in CR2 alone abolished the ability of the protein to self-interact. This laboratory previously reported that CR2 is also responsible for nuclear localization and nuclear matrix association (A. Yokoyama, Y. Kawaguchi, I. Kitabayashi, M. Ohki, and K. Hirai, Virology 279:401–413, 2001). (v) Sucrose gradient sedimentation showed that amino acid substitutions in CR2 reduced the ability of the protein to form protein complexes in B cells. These results suggest that self-association of EBNA-LP may be important for its various functions and interactions of the protein with multiple cellular proteins.

scholarly journals Amino-acid change in the Epstein-Barr-virus zebra protein in undifferentiated nasopharyngeal carcinomas from Europe and North Africa

1998 ◽  
Vol 75 (4) ◽  
pp. 497-503 ◽  
Author(s):  
Virginie Grunewald ◽  
Mathilde Bonnet ◽  
Sylvie Boutin ◽  
Timothy Yip ◽  
Hechmi Louzir ◽  
...  
Keyword(s):  
Amino Acid ◽  
North Africa ◽  
Epstein Barr Virus ◽  
Amino Acid Change ◽  
Barr Virus ◽  
Epstein Barr

scholarly journals Structure of the human B lymphocyte receptor for C3d and the Epstein-Barr virus and relatedness to other members of the family of C3/C4 binding proteins.

1988 ◽  
Vol 167 (3) ◽  
pp. 1047-1066 ◽  
Author(s):  
J J Weis ◽  
L E Toothaker ◽  
J A Smith ◽  
J H Weis ◽  
D T Fearon
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Epstein Barr Virus ◽  
Binding Proteins ◽  
Gene Sequence ◽  
B Lymphocyte ◽  
Factor H ◽  
Cdna Clones ◽  
Barr Virus ◽  
Epstein Barr

Human complement receptor type 2 (CR2) is the B lymphocyte receptor for C3d and the Epstein-Barr virus. This protein is also a member of a family of C3b/C4b binding proteins that regulate complement activation, comprise tandemly repeated 60-75 amino acid sequences, and whose genes map to band q32 on chromosome 1. Overlapping cDNA clones encoding the entire human CR2 protein have been isolated from a human tonsillar cDNA library. The derived amino acid sequence of 1,032 residues encodes a peptide of 112,716 mol wt. A signal peptide was identified, followed by 15 copies of the short consensus repeat (SCR) structure common to the C3/C4 binding protein family. The entire extracellular portion of the protein comprised SCRs, thus, the ligand binding sites both for C3d and the EBV protein gp350/220 are positioned within this structure. Immediately following the final SCR was a transmembrane sequence of 24 amino acids and a cytoplasmic region of 34 amino acids. One of five cDNA clones isolated contained an additional SCR, providing evidence for alternative mRNA splicing or gene products of different human alleles. The CR2 cDNAs were used to isolate CR2-specific genomic phage. The entire CR2 coding sequences were found within 20 kb of human DNA. Analysis of the CR2 cDNA sequence indicated that CR2 contained internally homologous regions and suggested that CR2 arose by duplication of a primordial gene sequence encoding four SCRs. Comparison of the CR2 peptide sequence with those of other members of the gene family has identified many regions highly homologous with human CR1, fewer with C4bp and decay accelerating factor, and very few with factor H, and suggested that CR2 and CR1 arose by duplication of the same ancestral gene sequence. The homology between CR2 and CR1 extended to the transmembrane and cytoplasmic regions, suggesting that these sequences were derived from a common membrane-bound precursor.

scholarly journals A Single Amino Acid in EBNA-2 Determines Superior B Lymphoblastoid Cell Line Growth Maintenance by Epstein-Barr Virus Type 1 EBNA-2

2014 ◽  
Vol 88 (16) ◽  
pp. 8743-8753 ◽  
Author(s):  
S. Tzellos ◽  
P. B. Correia ◽  
C. E. Karstegl ◽  
L. Cancian ◽  
J. Cano-Flanagan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Line ◽  
Virus Type ◽  
Epstein Barr Virus ◽  
Lymphoblastoid Cell Line ◽  
Single Amino Acid ◽  
Barr Virus ◽  
Epstein Barr
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