The cells of tumourigenic line SK-UT-1B combine features characteristic both of normal (diploid karyotype, a low level of polyploid cells, absence of chromosomal marker) and tumour cells (high level of chromosomal instability, high malignancy). We suggest that maintenance of diploid karyotype in this line is controlled via the p53/p21 pathway. We demonstrate that the amount of p53 increases following gamma-irradiation and accumulated p53 protein seems to be functional as p53-luc and p21/Waf-luc reporter plasmids were found to be activated. However, gamma-irradiation-induced increase of p53 was not accompanied by increase of p21/Waf on the protein level. Apparently this is one of the reasons for G1/S and G2/M checkpoint control disruption. The absence of these checkpoints could not prevent the proliferation of cells with intrachromosomal rearrangements. The only effective checkpoint in SK-UT-1B is the p53-dependent M checkpoint, which directed the cells with changed chromosome numbers to apoptosis and therefore strictly guarded the diploidy of the cell population. This indicates that p53 can control the preservation of genetic stability at different levels via different pathways.
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http://dx.doi.org/10.1006/cbir.2001.0709 | DOI Listing |
Naturwissenschaften
January 2025
Department of Biology, University of Washington, Seattle, WA, 98195, USA.
Four main classes of introns (group I, group II, spliceosomal, and archaeal) have been reported for all major types of RNA from nuclei and organelles of a wide range of taxa. When and how introns inserted within the genic regions of genomes, however, is often unclear. Introns were examined from Archaea, Bacteria, and Eukarya.
View Article and Find Full Text PDFJ Gen Virol
January 2025
Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan, ROC.
RNA structures that are functionally important are defined as -acting RNA elements because their functions cannot be compensated for in trans. The -acting RNA elements in the 3' UTR of coronaviruses are important for replication; however, the mechanism linking the -acting RNA elements to their replication function remains to be established. In the present study, a comparison of the biological processes of the interactome and the replication efficiency between the 3' UTR -acting RNA elements in coronaviruses, including severe acute respiratory syndrome coronavirus 2, suggests that (i) the biological processes, including translation, protein folding and protein stabilization, derived from the analysis of the -acting RNA element interactome and (ii) the architecture of the -acting RNA elements and their interactomes are highly correlated with coronavirus replication.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
RNA endonucleases are the rate-limiting initiator of decay for many bacterial mRNAs. However, the positions of cleavage and their sequence determinants remain elusive even for the well-studied Bacillus subtilis. Here we present two complementary approaches-transcriptome-wide mapping of endoribonucleolytic activity and deep mutational scanning of RNA cleavage sites-that reveal distinct rules governing the specificity among B.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Division of Plant Science and Technology, University of Missouri, Columbia, MO 65211, United States.
G-quadruplex (G4) structure is a nucleic acid secondary structure formed by guanine-rich sequences, playing essential roles in various biological processes such as gene regulation and environmental stress adaptation. Although prokaryotes growing at high temperatures have higher GC contents, the pattern of G4 structure associated with GC content variation in thermal adaptation remains elusive. This study analyzed 681 bacterial genomes to explore the role of G4 structures in thermal adaptation.
View Article and Find Full Text PDFJ Med Chem
January 2025
AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States.
Cystic fibrosis (CF) is a genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which regulates ion and fluid transport across epithelial cells. Mutations lead to complications, with life-limiting lung disease being the most severe manifestation. Traditional treatments focused on managing symptoms, but advances in understanding CF's molecular basis led to small-molecule CFTR modulators.
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