A highly efficient UGA stop codon readthrough event during the synthesis of human neurotrophin 3 in E. coli is described. The incorporation of a Trp residue at the UGA stop codon is confirmed combining both the chemical analyses and the molecular and genetic data in this report. The 3' adjacent nuleotide to the UGA stop codon plays a crucial role in determining the readthrough efficiency in the order of A > G > C > U. The replacement of UGA with UAA or UAG totally abolished this readthrough phenomenon and the use of StpR host cells also prevented the occurrence of UGA readthrough. Gene dosage (or plasmid copy number) effect was not indicated in this event; however, the titration of RF-2 by mRNA transcripts under over-expression conditions might explain why tRNAtrp competes so well with RF-2 for UGA. Another apparently less produced readthrough product resulting from a transcript with no stop codon is also recorded, and the addition of a second in-frame stop codon increased the amount of the observed readthrough product.
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http://dx.doi.org/10.1006/bbrc.1995.1775 | DOI Listing |
Biomedica
December 2024
Grupo de Inmunodeficiencias Primarias, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
Introduction: Common variable immunodeficiency is a diagnosis of exclusion in immunodeficient patients with increased susceptibility to infections, hypogammaglobulinemia, deficient response to vaccination, or low percentages of switched memory B cells. In low- and middle-income countries, the elucidation and study of molecular defects in these patients may take decades.
Objective: To elucidate the genetic defect conferring impaired immunity in a patient diagnosed with common variable immunodeficiency.
Mol Phylogenet Evol
January 2025
Charles University, Faculty of Science, Department of Zoology, Prague, Czechia.
The phylum Heterolobosea Page and Blanton, 1985 is a group of eukaryotes that contains heterotrophic flagellates, amoebae, and amoeboflagellates, including the infamous brain-eating amoeba Naegleria fowleri. In this study, we investigate the deep evolutionary history of Heterolobosea by generating and analyzing transcriptome data from 16 diverse isolates and combine this with previously published data in a comprehensive phylogenomic analysis. This dataset has representation of all but one of the major lineages classified here as orders.
View Article and Find Full Text PDFPLoS Genet
January 2025
Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Inositol 1,4,5-trisphosphate receptors (IP3R) mediate Ca2+ release from intracellular stores, contributing to complex regulation of numerous physiological responses. The involvement of the three IP3R genes (ITPR1, ITPR2 and ITPR3) in inherited human diseases has started to shed light on the essential roles of each receptor in different human tissues and cell types. Variants in the ITPR3 gene, which encodes IP3R3, have recently been found to cause demyelinating sensorimotor Charcot-Marie-Tooth neuropathy type 1J (CMT1J).
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Division of Pharmacoengineering and Molecular Pharmaceutics, The University of North Carolina at Chapel Hill, 125 Mason Farm Rd. Chapel Hill, NC 27599, USA.
Whole genome codon compression-the reassignment of all instances of a specific codon to synonymous codons-can generate organisms capable of tolerating knockout of otherwise essential transfer RNAs (tRNAs). As a result, such knockout strains enable numerous unique applications, such as high-efficiency production of DNA encoding extremely toxic genes or non-canonical proteins. However, achieving stringent control over protein expression in these organisms remains challenging, particularly with proteins where incomplete repression results in deleterious phenotypes.
View Article and Find Full Text PDFAnn Med
December 2025
Department of Basic Medical Sciences, College of Medicine & Center for Genetics and Inherited Diseases, Taibah University Medina, Medina, Saudi Arabia.
Background: Peroxisome biogenesis disorders (PBD) affect multiple organ systems. It is characterized by neurological dysfunction, hypotonia, ocular anomalies, craniofacial abnormalities, and absence of peroxisomes in fibroblasts. PBDs are associated with mutations in any of fourteen different genes, which are involved in peroxisome biogenesis.
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