The v-myb oncogene of the avian myeloblastosis virus encodes a nuclear protein, p48v-myb, which binds to DNA in a sequence-specific manner. We have used wild type and mutant forms of this protein expressed in E. coli to study the protein and DNA determinants for sequence-specific DNA-binding. We have shown that only the highly conserved domain at the amino terminus of p48v-myb is required for sequence-specific DNA-binding. However, neither of the tandem 50 amino acid repeats present in this domain is alone sufficient for such binding. We have also demonstrated that p48v-myb can recognize a single consensus myb binding site and appears to interact with DNA as a protein monomer. In addition, we have shown that sequence-specific binding by p48v-myb requires nucleotides which flank the previously reported PyAACT/GG consensus.
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PLoS Biol
January 2025
Institute of Biochemistry, ETH Zürich, Zürich, Switzerland.
Noncoding satellite DNA repeats are abundant at the pericentromeric heterochromatin of eukaryotic chromosomes. During interphase, sequence-specific DNA-binding proteins cluster these repeats from multiple chromosomes into nuclear foci known as chromocenters. Despite the pivotal role of chromocenters in cellular processes like genome encapsulation and gene repression, the associated proteins remain incompletely characterized.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou 510630, China.
Epstein-Barr nuclear antigen 1 (EBNA1), a sequence-specific DNA binding protein of Epstein-Barr virus (EBV), is essential for viral genome replication and maintenance and is therefore an attractive target for the therapeutic intervention of EBV-associated cancers. Several EBNA1-specific inhibitors have demonstrated the ability to block EBNA1 function in vitro, but practical delivery strategies for these inhibitors in vivo are still lacking. Here, we report an intelligent hierarchical targeting theranostic nanosystem (denoted as mZGOCS@MnO-P5) that integrates an azide (N3) terminal dual-targeting peptide (N3-P5), a tumor microenvironment-responsive degradable MnO nanosheet, and a mesoporous ZnGaO:Cr, Sn near-infrared persistent luminescence (NIR-PL) nanosphere (mZGOCS).
View Article and Find Full Text PDFJ Biomol Struct Dyn
February 2025
Laboratory of Integrative Genomics, Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, India.
The P53 protein, a cancer-associated transcriptional factor and tumor suppressor, houses a Zn ion in its DNA-binding domain (DBD), essential for sequence-specific DNA binding. However, common mutations at position 273, specifically from Arginine to Histidine and Cysteine, lead to a loss of function as a tumor suppressor, also called DNA contact mutations. The mutant (MT) P53 structure cannot stabilize DNA due to inadequate interaction.
View Article and Find Full Text PDFInt J Biol Sci
December 2024
State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200032, China.
Nuclear receptor subfamily 4 group A member 3 (NR4A3) is a member of the orphan nuclear receptor superfamily, and exhibits transcription factor activity by binding to sequence-specific DNA. Considering that the specific mechanism by which NR4A3 regulates gene transcription in HCC (hepatocellular carcinoma) has not yet been elucidated, our study aimed to explore the transcriptional role of NR4A3 in regulating the target gene CDKN2AIP (CDKN2A interacting protein), which will suppress the development of HCC. Our data show that NR4A3 is downregulated in human HCC tissues, and that low expression of NR4A3 is correlated with poor prognosis, indicating that NR4A3 could act as a tumor suppressor gene in HCC.
View Article and Find Full Text PDFMethods Mol Biol
November 2024
Bioinformatics Group, Babraham Institute, Cambridge, UK.
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