The human DNA-dependent activator of IFN-regulatory factor (DAI) protein, which activates the innate immune response in response to DNA, contains two tandem Z-DNA binding domains (Zα and Zβ) at the NH(2) terminus. The hZβ(DAI) structure is similar to other Z-DNA binding proteins, although it demonstrates an unusual Z-DNA recognition. We performed NMR experiments on complexes of hZβ(DAI) with DNA duplex, d(CGCGCG)(2), at a variety of protein-to-DNA molar ratios. The results suggest that hZβ(DAI) binds to Z-DNA via an active-di B-Z transition mechanism, where two hZβ(DAI) proteins bind to B-DNA to form the hZβ(DAI)-B-DNA complex; the B-DNA is subsequently converted to left-handed Z-DNA. This novel mechanism of DNA binding and B-Z conversion is distinct from Z-DNA binding of the human ADAR1 protein.
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http://dx.doi.org/10.1016/j.febslet.2011.01.043 | DOI Listing |
Trends Biochem Sci
December 2024
Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC 3052, Australia; Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia. Electronic address:
Necroptosis is a mode of programmed cell death executed by the mixed lineage kinase domain-like (MLKL) pseudokinase following its activation by the upstream receptor-interacting protein kinase-3 (RIPK3), subsequent to activation of death, Toll-like, and pathogen receptors. The pathway originates in innate immunity, although interest has surged in therapeutically targeting necroptosis owing to its dysregulation in inflammatory diseases. Here, we explore how protein conformation and higher order assembly of the pathway effectors - Z-DNA-binding protein-1 (ZBP1), RIPK1, RIPK3, and MLKL - can be modulated by post-translational modifications, such as phosphorylation, ubiquitylation, and lipidation, and intermolecular interactions to tune activities and modulate necroptotic signaling flux.
View Article and Find Full Text PDFPharmacol Res
December 2024
Center for Drug Research and Development, Guangdong Pharmaceutical University, Guangzhou 510006, China; Key specialty of Clinical Pharmacy, The first Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510699, China. Electronic address:
Ulcerative colitis (UC) is characterized by increased cell death in intestinal epithelial cell (IEC), which compromises gut barrier function and activates inflammation. Aberrant mitochondrial dynamics have been implicated in various forms of cell death, but it is currently unclear if they play a role in IEC death and colitis pathogenesis. This study aims to investigate the contribution of aberrant mitochondrial dynamics to colitis progression using cellular models, animal models, and clinical samples.
View Article and Find Full Text PDFbioRxiv
November 2024
Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Transcription factors (TFs) are key players in eukaryotic gene regulation, but the DNA binding specificity of many TFs remains unknown. Here, we assayed 284 mostly poorly characterized, putative human TFs using selective microfluidics-based ligand enrichment followed by sequencing (SMiLE-seq), revealing 72 new DNA binding motifs. To investigate whether some of the 158 TFs for which we did not find motifs preferably bind epigenetically modified DNA (i.
View Article and Find Full Text PDFVet Sci
November 2024
Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China.
Influenza A virus (IAV) infection initiates a complex interplay of cell death modalities, including apoptosis, necroptosis, pyroptosis, and their integration, known as PANoptosis, which significantly impacts host immune responses and tissue integrity. These pathways are intricately regulated by viral proteins and host factors, contributing to both viral clearance and pathogenesis-related tissue damage. This review comprehensively explores the molecular mechanisms underlying these cell death processes in influenza infection.
View Article and Find Full Text PDFBMC Genomics
November 2024
Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, 300044, Taiwan.
Background: Z-DNA, a left-handed helical form of DNA, plays a significant role in genomic stability and gene regulation. Its formation, associated with high GC content and repetitive sequences, is linked to genomic instability, potentially leading to large-scale deletions and contributing to phenotypic diversity and evolutionary adaptation.
Results: In this study, we analyzed the density of Z-DNA-prone motifs of 154 avian genomes using the non-B DNA Motif Search Tool (nBMST).
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