Previous studies have demonstrated that the 21- or the 72-bp repeat transcriptional control elements enhance the efficiency of SV40 DNA replication in vivo, provided either of these repeats is located near the end of the core replication origin containing the 17-bp A + T-containing sequence. Using two sets of point mutants we have investigated the contributions of the various sequence motifs present in the 21- or the 72-bp repeats toward activation of replication. Regarding the contribution of the six GC motif components of the 21-bp repeats, we find that GC motif I, located closest to the core origin, is dispensable for activation of replication. A mutation in GC-I in fact causes an increase in replication efficiency. We also find that GC motifs I and II present in the nontandem copy of the 21-bp repeats are not sufficient to activate replication. Our present study indicates that a combination of three GC motifs such as II, III, and IV (including one of the two perfect, tandem copies of the 21-bp repeats) is important for activation of replication. Regarding the 72-bp repeat transcriptional enhancer region, we find mutations in a number of its individual motifs to have a negative consequence on replication, with mutations in the GT-I*/TC-II and Sph-II/octamer motifs exhibiting the most negative effects. Overall, we find that the replication activation effects of the 21- and the 72-bp repeats require the participation of multiple motifs present in them. Cellular factors binding to these motifs are expected to mediate their replication activation effects. For the most part, the motifs required for activation of replication are the same as those reported in earlier studies to be important for efficient early and late viral mRNA transcription.
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http://dx.doi.org/10.1016/0042-6822(91)90007-x | DOI Listing |
Cancer Chemother Pharmacol
January 2025
Cancer Therapeutics Program, UPMC Hillman Cancer Center, Pittsburgh, PA, USA.
Background: ATR is an apical DDR kinase activated at damaged replication forks. Elimusertib is an oral ATR inhibitor and potentiates irinotecan in human colorectal cancer models.
Methods: To establish dose and tolerability of elimusertib with FOLFIRI, a Bayesian Optimal Interval trial design was pursued.
Org Biomol Chem
January 2025
Department of Pharmaceutical & Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602, USA.
Bacterial biofilms are surface-attached communities consisting of non-replicating persister cells encased within an extracellular matrix of biomolecules. Unlike bacteria that have acquired resistance to antibiotics, persister cells enable biofilms to demonstrate innate tolerance toward all classes of conventional antibiotic therapies. It is estimated that 50-80% of bacterial infections are biofilm associated, which is considered the underlying cause of chronic and recurring infections.
View Article and Find Full Text PDFWhile key for pathogen immobilization, neutrophil extracellular traps (NETs) often cause severe bystander cell/tissue damage. This was hypothesized to depend on their prolonged presence in the vasculature, leading to cytotoxicity. Imaging of NETs (histones, neutrophil elastase, extracellular DNA) with intravital microscopy in blood vessels of mouse livers in a pathogen-replicative-free environment (endotoxemia) led to detection of NET proteins attached to the endothelium for months despite the early disappearance of extracellular DNA.
View Article and Find Full Text PDFJ Virol
January 2025
State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou University, Lanzhou, China.
Lumpy skin disease virus (LSDV) infection poses a significant threat to global cattle farming. Currently, effective therapeutic agents are lacking. TMP269, a small molecule inhibitor of class IIa histone deacetylase inhibitor, plays a vital role in cancer therapy.
View Article and Find Full Text PDFJ Virol
January 2025
College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China.
Unlabelled: Avian leukosis virus subgroup J (ALV-J) poses a significant threat to the poultry industry; yet, our understanding of its replication and pathogenic mechanisms is limited. The Ten-Eleven Translocation 2 (TET2) is an indispensable regulatory factor in active DNA demethylation and immune response regulation. This study reports a significant and time-dependent decrease in TET2 levels following ALV-J infection and shows that the reduction of TET2 protein is mediated by the autophagy pathway.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!