Method: The plasmids pHD1013/Z, pHD1013/Z(S186A), pHD1013/Z(S186E), pHD1013/Z(R179A), pHD1013/Z(R183E), pHD1013/Z(N182E) were described previously.
Resul
Result: As seen with wild-type ZEBRA (Fig 9A and 9B and Fig 10A:ii), the Z(S186A) (Fig 10A:iii and 10B) and Z(N182E) (Fig 10A:iv and 10B) mutants induced pATM foci in a significant proportion of 293 cells relative to the negative control (Fig 10B).
Nuclear translocation and regulation of intranuclear distribution of cytoplasmic poly(A)-binding protein are distinct processes mediated by two Epstein Barr virus proteins.
Result: Although Z(S186A) efficiently binds to three ZREs, ZRE-R1, ZIIIA, and ZIIIB, as well as the AP-1 octamer site, this mutant is deficient in binding to methylated ZRE-R3 in the promoter of the EBV gene encoding Rta.
Result: Cell counts (Table 2) showed no significant decrease in PABPC translocation by Z(N182K) (58.6% of 133 cells) or by Z(S186A) (65.6% of 131 cells) compared to WT ZEBRA (60.9% of 174 cells).
Result: To investigate mechanisms by which activities of ZEBRA regulate translocation and intranuclear distribution of PABPC, we used three point mutants of ZEBRA, Z
Essential role of Rta in lytic DNA replication of Epstein-Barr virus.
Abstract: Ectopic expression of the six components of the EBV lytic replication machinery failed to rescue replication by Z(S186A).
Abstract: However, addition of Rta to Z(S186A) and the mixture of replication factors activated viral replication and late gene expression.
Abstract: In addition, expression of Rta and Z(S186A) together, but not individually, activated synthesis of the BHLF1 transcript, a lytic transcript required for the process of viral DNA replication.
Abstract: We found that Z(S186A), a mutant of ZEBRA unable to a
Two phenylalanines in the C-terminus of Epstein-Barr virus Rta protein reciprocally modulate its DNA binding and transactivation function.
Method: pRTS, pRTS/Rta, RpCAT (-299/+58), BMLF1(RRE)/CAT and CMV/Z(S186A) have been described.
Result: 2) behaved like wild-type in activating EA-D, alone and in synergy with Z(S186A), and in activation of BLRF2.
Result: 5A (lane 3) and 5B (lane 3) show that two deletion mutants of Rta which were enhanced in DNA binding did not detectably activate EA-D protein when they were introduced into BZKO cells together with Z(S186A).
Result: 6) compared transcriptional activation by the Rta (F600A/
Methylation-dependent binding of the epstein-barr virus BZLF1 protein to viral promoters.
Abstract: The Z(S186A) mutant cannot activate methylated Nap in reporter gene assays and does not induce Na expression in cells with latent EBV infection.
Introduction: We also demonstrate that the CpG motifs in the Nap ZREs are usually methylated on the EBV genome during latent infection, and that a Z mutant, Z(S186A), which cannot bind to the methylated Nap ZREs in vitro is unable to activate Na expression in latently infected cells.
Method: Structures of Z bound to four different ZREs were modeled based on the crystal structure of Z (S186A, C189S) bound to the AP1 site (PDB code: 2c9l) using the Sybyl p
Methylated DNA recognition during the reversal of epigenetic silencing is regulated by cysteine and serine residues in the Epstein-Barr virus lytic switch protein.
Introduction: A previous study had shown that the point mutation S186A compromises Zta's ability to bind both the methylated and non-methylated forms of the ZREs within Rp.
Result: As shown in Figure 8C, ZtaS186A binds more weakly to meZRE2 than does wild type Zta, in agreement with previous studies; omitting the cytosine-2 methyl group further decreases the relative binding affinity, consistent with the loss of an important contact.
Result: Our model predicts that omitting this group should more significantly compromise the binding affinity (relative to wild type) of the S186A mutant over that of the C189S mutant, because only the former conserves the cysteine thiol group.
Result: We next investigated the contribution of
Mutations of amino acids in the DNA-recognition domain of Epstein-Barr virus ZEBRA protein alter its sub-nuclear localization and affect formation of replication compartments.
Abstract: Co-expression of Rta with S186A mutant rescued diffuse EA-D but not globular replication compartments.
Abstract: The distribution of S186A mutant ZEBRA protein, defective for activation of Rta and EA-D, was identical to WT, except that the mutant ZEBRA was never found in globular compartments.
Result: 2089 cells co-transfected with S186A and Rta-expression plasmids were stained for ZEBRA and EA-D, as a marker for Rta activity.
Result: Both mutations completely abolish PMID: 16406456
2006
Virology
Abstract: However, a co-operative effect between ZEBRA and RTA in the expression of BFRF1 is evident since the transfection of RTA can rescue the transactivating capacity of a mutant of the ZEBRA protein, known as Z(S186A), that has a substitution affecting the DNA binding region.
BZLF1 activation of the methylated form of the BRLF1 immediate-early promoter is regulated by BZLF1 residue 186.
Abstract: A Z mutant containing an alanine residue at position 186 [Z(S186A)] was significantly defective in binding to methylated, as well as unmethylated, ZREs (Z-responsive elements) in Rp and was unable to activate lytic EBV gene transcription from the methylated or demethylated form of the viral genome.
A redox-sensitive cysteine in Zta is required for Epstein-Barr virus lytic cycle DNA replication.
Abstract: C189S was not defective in binding methylated DNA binding sites and was capable of activating Rta from endogenous latent viral genomes, in contrast to the previously characterized S186A mutation.
EBV mutation literature information.
PMID: 
2015
PloS one
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