Project description:The Epstein-Barr virus (EBV) bZIP transcription factor (TF) Zta is a sequence-specific DNA binding protein that recognizes both unmethylated and methylated DNA. To study the contribution of the conserved N182 amino acid to sequence specific Zta DNA binding, we replaced it with five other amino acids: serine (S), glutamine (Q), threonine (T), isoleucine (I), or valine (V). We used protein binding microarrays (PBMs) to evaluate sequence-specific DNA binding to four types of double-stranded DNA: 1) DNA with cytosine in both strands (DNA(C|C), 2) DNA with 5-methylcytosine (5mC, M) in one strand and cytosine in the second strand (DNA(5mC|C)), 3) DNA with 5-hydroxymethylcytosine (5hmC, H) in one strand and cytosine in the second strand (DNA(5hmC|C)), and 4) DNA with methylated cytosine in both strands in all CG dinucleotides (DNA(5mCG)). With unmethylated DNA, Zta(N182S) binds variants of the consensus TRE (TGA-G/C-TCA) motif, such as TGA-G/C-TGA and TCA-G/C-TGA where C at position 3 is replaced with G in one or both half sites of the motif. Zta(N182S) also binds stronger to DNAs containing modified cytosines compared to wildtype. Zta(N182Q) binds new sequences containing GTAA with DNA(C|C), DNA(5mC|C) and DNA(5hmC|C) where C at position 3 is replaced with A. Zta(N182I) and Zta(N182V) bind sequence specifically to DNA(5mC|C), and weakly with all other types of DNA examined. Zta(N182T) DNA binding is weaker to all types of DNA examined. Our data highlight that mutation of ZtaN182 with the hydrophilic amino acids serine and glutamine alters Zta sequence specific DNA binding, while mutation with hydrophobic amino acids (I and V) increases binding to DNA(5mC|C).
Project description:The Epstein-Barr virus (EBV) bZIP transcription factor (TF) Zta is a sequence-specific DNA binding protein that recognizes both unmethylated and methylated DNA. To study the contribution of the conserved N182 amino acid to sequence specific Zta DNA binding, we replaced it with five other amino acids: serine (S), glutamine (Q), threonine (T), isoleucine (I), or valine (V). We used protein binding microarrays (PBMs) to evaluate sequence-specific DNA binding to four types of double-stranded DNA: 1) DNA with cytosine in both strands (DNA(C|C), 2) DNA with 5-methylcytosine (5mC, M) in one strand and cytosine in the second strand (DNA(5mC|C)), 3) DNA with 5-hydroxymethylcytosine (5hmC, H) in one strand and cytosine in the second strand (DNA(5hmC|C)), and 4) DNA with methylated cytosine in both strands in all CG dinucleotides (DNA(5mCG)). With unmethylated DNA, Zta(N182S) binds variants of the consensus TRE (TGA-G/C-TCA) motif, such as TGA-G/C-TGA and TCA-G/C-TGA where C at position 3 is replaced with G in one or both half sites of the motif. Zta(N182S) also binds stronger to DNAs containing modified cytosines compared to wildtype. Zta(N182Q) binds new sequences containing GTAA with DNA(C|C), DNA(5mC|C) and DNA(5hmC|C) where C at position 3 is replaced with A. Zta(N182I) and Zta(N182V) bind sequence specifically to DNA(5mC|C), and weakly with all other types of DNA examined. Zta(N182T) DNA binding is weaker to all types of DNA examined. Our data highlight that mutation of ZtaN182 with the hydrophilic amino acids serine and glutamine alters Zta sequence specific DNA binding, while mutation with hydrophobic amino acids (I and V) increases binding to DNA(5mC|C).
Project description:The Epstein-Barr virus (EBV) bZIP transcription factor (TF) Zta is a sequence-specific DNA binding protein that recognizes both unmethylated and methylated double stranded DNA (dsDNA). To study the contribution to sequence specific dsDNA binding of the conserved asparagine in the DNA binding region (Zta(N182)), we replaced it with five other amino acids: serine (S), glutamine (Q), threonine (T), isoleucine (I), or valine (V). We used protein binding microarrays (PBMs) to evaluate sequence-specific DNA binding to four types of dsDNA: 1) DNA with cytosine in both strands (DNA(C|C), 2) DNA with 5-methylcytosine (5mC, M) in one strand and cytosine in the second strand (DNA(5mC|C)), 3) DNA with 5-hydroxymethylcytosine (5hmC, H) in one strand and cytosine in the second strand (DNA(5hmC|C)), and 4) DNA with methylated cytosine in both strands in all CG dinucleotides (DNA(5mCG)). With unmethylated DNA, Zta binds the consensus TRE motif, also known as the AP1 motif (T-4G-3A-2G/C0T2C3A4). Zta(N182S) binds the variants andwhere C3 is replaced with G3 in one (T-4G-3A-2G/CT2G3A4) or both T-4C-3A-2G/CT2G3A4 half sites. Zta(N182S) also binds stronger to DNA containing modified cytosines compared to wildtype. Zta(N182Q) binds new sequences containing G0T2A3A4 with DNA(C|C), DNA(5mC|C) and DNA(5hmC|C) where C3 is replaced with A3 only on one half site. Zta(N182I) and Zta(N182V) bind sequence specifically to DNA(5mC|C), and weakly with all other types of DNA examined. Zta(N182T) DNA binding is weaker to all types of DNA examined. Our data highlights that mutation of Zta(N182) with the hydrophilic amino acids serine and glutamine alters Zta sequence specific DNA binding, while mutation with hydrophobic amino acids (I and V) increases binding to DNA(5mC|C).
Project description:The Epstein-Barr virus (EBV) bZIP transcription factor (TF) Zta is a sequence-specific DNA binding protein that recognizes both unmethylated and methylated double stranded DNA (dsDNA). To study the contribution to sequence specific dsDNA binding of the conserved asparagine in the DNA binding region (Zta(N182)), we replaced it with five other amino acids: serine (S), glutamine (Q), threonine (T), isoleucine (I), or valine (V). We used protein binding microarrays (PBMs) to evaluate sequence-specific DNA binding to four types of dsDNA: 1) DNA with cytosine in both strands (DNA(C|C), 2) DNA with 5-methylcytosine (5mC, M) in one strand and cytosine in the second strand (DNA(5mC|C)), 3) DNA with 5-hydroxymethylcytosine (5hmC, H) in one strand and cytosine in the second strand (DNA(5hmC|C)), and 4) DNA with methylated cytosine in both strands in all CG dinucleotides (DNA(5mCG)). With unmethylated DNA, Zta binds the consensus TRE motif, also known as the AP1 motif (T-4G-3A-2G/C0T2C3A4). Zta(N182S) binds the variants andwhere C3 is replaced with G3 in one (T-4G-3A-2G/CT2G3A4) or both T-4C-3A-2G/CT2G3A4 half sites. Zta(N182S) also binds stronger to DNA containing modified cytosines compared to wildtype. Zta(N182Q) binds new sequences containing G0T2A3A4 with DNA(C|C), DNA(5mC|C) and DNA(5hmC|C) where C3 is replaced with A3 only on one half site. Zta(N182I) and Zta(N182V) bind sequence specifically to DNA(5mC|C), and weakly with all other types of DNA examined. Zta(N182T) DNA binding is weaker to all types of DNA examined. Our data highlights that mutation of Zta(N182) with the hydrophilic amino acids serine and glutamine alters Zta sequence specific DNA binding, while mutation with hydrophobic amino acids (I and V) increases binding to DNA(5mC|C).
Project description:Epstein-Barr virus (EBV) is present in a state of latency in infected memory B-cells and EBV-associated lymphoid and epithelial cancers. Cell stimulation or differentiation of infected B-cells and epithelial cells induces reactivation to the lytic replication cycle. In each cell type, the EBV transcription and replication factor Zta (BZLF1, EB1) plays a role in mediating the lytic cycle of EBV. Zta is a transcription factor that interacts directly with Zta response elements (ZREs) within viral and cellular genomes. Here we undertake chromatin-precipitation coupled to DNA-sequencing (ChIP-Seq) of Zta-associated DNA from cancer-derived epithelial cells. The analysis identified over 14,000 Zta-binding sites in the cellular genome. We assessed the impact of lytic cycle reactivation on changes in gene expression for a panel of Zta-associated cellular genes. Finally, we compared the Zta-binding sites identified in this study with those previously identified in B-cells and reveal substantial conservation in genes associated with Zta-binding sites.
Project description:Zta is a bZIP transcription factor (TF) in the Epstein-Barr virus that binds unmethylated and methylated DNA sequences. Substitution of cysteine 189 of Zta to serine (Zta(C189S)) results in a virus that is unable to execute the lytic cycle which was attributed to a change in binding to methylated DNA sequences. To learn more about the role of this position in defining sequence-specific DNA binding, we mutated cysteine 189 to four other amino acids producing Zta(C189S), Zta(C189T), Zta(C189A), and Zta(C189V) mutants. Zta and mutants were used in protein binding microarray (PBM) experiments to evaluate sequence-specific DNA binding to four types of double-stranded DNA (dsDNA): 1) with cytosine in both strands (DNA(C|C)), 2) with 5-methylcytosine (5mC) in one strand and cytosine in the second strand (DNA(5mC|C)), 3) with 5-hydroxymethylcytosine (5hmC) in one strand and cytosine in the second strand (DNA(5hmC|C)), and 4) with both cytosines in all CG dinucleotides containing 5mC (DNA(5mCG)). Zta(C189S) and Zta(C189T) bound the TRE (AP-1) motif (TGAG/CTCA) more strongly than wild-type Zta, while binding to other sequences, including the C/EBP half site GCAA was reduced. Binding of Zta(C189S) and Zta(C189T) to DNA containing modified cytosines (DNA(5mC|C), DNA(5hmC|C), and DNA(5mCG)) was reduced compared to Zta. Zta(C189A) and Zta(C189V) had higher non-specific binding to all four types of DNA. Our data suggests that position C189 in Zta impacts sequence-specific binding to DNA containing modified and unmodified cytosine.