Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Autogenous suppression of an opal mutation in the gene encoding peptide chain release factor 2.

ABSTRACT: The peptide chain release factor 2 (RF2) gene, prfB, was cloned from Salmonella typhimurium by DNA hybridization using the Escherichia coli prfB probe. The nucleotide and amino acid sequences of prfB are 87.0% and 95.6% homologous between E. coli and S. typhimurium, respectively, including an in-frame premature UGA stop codon at position 26, the site of +1 frameshift for mature RF2 synthesis. The supK584 mutation, which had been isolated as a recessive UGA suppressor in S. typhimurium, caused an opal (UGA) substitution at amino acid position 144 in the prfB gene. Complementation, reversion, and gene fusion analyses led to the conclusion that supK is a S. typhimurium RF2 mutation and this opal RF2 mutation generates a UGA suppressor activity, presumably because of inefficient translation termination due to the reduced cellular level of RF2. In fact, suppression of the supK opal mutation results from a form of autogenous control of RF2 synthesis.

SUBMITTER: Kawakami K

PROVIDER: S-EPMC54970 | biostudies-other | 1990 Nov

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Autogenous suppression of an opal mutation in the gene encoding peptide chain release factor 2.

Kawakami K K Nakamura Y Y

Proceedings of the National Academy of Sciences of the United States of America 19901101 21

The peptide chain release factor 2 (RF2) gene, prfB, was cloned from Salmonella typhimurium by DNA hybridization using the Escherichia coli prfB probe. The nucleotide and amino acid sequences of prfB are 87.0% and 95.6% homologous between E. coli and S. typhimurium, respectively, including an in-frame premature UGA stop codon at position 26, the site of +1 frameshift for mature RF2 synthesis. The supK584 mutation, which had been isolated as a recessive UGA suppressor in S. typhimurium, caused an ...[more]

PMID: 2236050

Similar Datasets

Identification of the prfC gene, which encodes peptide-chain-release factor 3 of Escherichia coli.

Project description:The termination of protein synthesis in bacteria requires two codon-specific polypeptide release factors, RF-1 and RF-2. A third factor, RF-3, which stimulates the RF-1 and RF-2 activities, was originally identified in Escherichia coli, but it has received little attention since the 1970s. To search for the gene encoding RF-3, we selected nonsense-suppressor mutations by random insertion mutagenesis on the assumption that a loss of function of RF-3 would lead to misreading of stop signals. One of these mutations, named tos-1 (for transposon-induced opal suppressor), mapped to the 99.2 min region on the E. coli chromosome and suppressed all three stop codons. Complementation studies and analyses of the DNA and protein sequences revealed that the tos gene encodes a 59,442-Da protein, with sequence homology to elongation factor EF-G, including G-domain motifs, and that the tos-1 insertion eliminated the C-terminal one-fifth of the protein. Extracts containing the overproduced Tos protein markedly increased the formation of ribosomal termination complexes and stimulated the RF-1 or RF-2 activity in the codon-dependent in vitro termination assay. The stimulation was significantly reduced by GTP, GDP, and the beta,gamma-methylene analog of GTP, but not by GMP. These results fit perfectly with those described in the original publications on RF-3, and the tos gene has therefore been designated prfC. A completely null prfC mutation made by reverse genetics affected the cell growth under the limited set of physiological and strain conditions.

| S-EPMC44084 | biostudies-other

The Peptide Chain Release Factor Methyltransferase PrmC Influences the Pseudomonas aeruginosa PA14 Endo- and Exometabolome.

Project description:Pseudomonas aeruginosa is one of the most important nosocomial pathogens and understanding its virulence is the key to effective control of P. aeruginosa infections. The regulatory network governing virulence factor production in P. aeruginosa is exceptionally complex. Previous studies have shown that the peptide chain release factor methyltransferase PrmC plays an important role in bacterial pathogenicity. Yet, the underlying molecular mechanism is incompletely understood. In this study, we used untargeted liquid and gas chromatography coupled to mass spectrometry to characterise the metabolome of a prmC defective P. aeruginosa PA14 strain in comparison with the corresponding strain complemented with prmC in trans. The comprehensive metabolomics data provided new insight into the influence of prmC on virulence and metabolism. prmC deficiency had broad effects on the endo- and exometabolome of P. aeruginosa PA14, with a marked decrease of the levels of aromatic compounds accompanied by reduced precursor supply from the shikimate pathway. Furthermore, a pronounced decrease of phenazine production was observed as well as lower abundance of alkylquinolones. Unexpectedly, the metabolomics data showed no prmC-dependent effect on rhamnolipid production and an increase in pyochelin levels. A putative virulence biomarker identified in a previous study was significantly less abundant in the prmC deficient strain.

| S-EPMC7650828 | biostudies-literature

Thrombocytopenia and erythrocytosis in mice with a mutation in the gene encoding the hemoglobin ? minor chain.

Project description:Diverse mutations in the genes encoding hemoglobin (Hb) have been characterized in human disease. We describe here a mutation in the mouse Hbb-b2 gene, denoted Plt12, that precisely mimics the human hemoglobin Hotel Dieu variant. The mutation results in increased affinity of Hb for oxygen and Plt12 mutant mice exhibited reduced partial pressure of O(2) in the blood, accompanied by erythrocytosis characterized by elevated erythropoietin levels and splenomegaly with excess erythropoiesis. Most homozygous Hbb-b2(Plt12/Plt12) mice succumbed to early lethality associated with emphysema, cardiac abnormalities, and liver degeneration. Survivors displayed a marked thrombocytopenia without significant deficiencies in the numbers of megakaryocytes or megakaryocyte progenitor cells. The lifespan of platelets in the circulation of Hbb-b2(Plt12/Plt12) mice was normal, and splenectomy did not correct the thrombocytopenia, suggesting that increased sequestration was unlikely to be a major contributor. These data, together with the observation that megakaryocytes in Hbb-b2(Plt12/Plt12) mice appeared smaller and deficient in cytoplasm, support a model in which hypoxia causes thrombocytopenia as a consequence of an inability of megakaryocytes, once formed, to properly mature and produce sufficient platelets. The Plt12 mouse is a model of high O(2)-affinity hemoglobinopathy and provides insights into hematopoiesis under conditions of chronic hypoxia.

| S-EPMC3258592 | biostudies-literature

The yeast nuclear gene MRF1 encodes a mitochondrial peptide chain release factor and cures several mitochondrial RNA splicing defects.

Project description:We report the molecular cloning, sequencing and genetic characterization of the first gene encoding an organellar polypeptide chain release factor, the MRF1 gene of the yeast Saccharomyces cerevisiae. The MRF1 gene was cloned by genetic complementation of a respiratory deficient mutant disturbed in the expression of the mitochondrial genes encoding cytochrome c oxidase subunit 1 and 2, COX1 and COX2. For COX1 this defect has been attributed to an impaired processing of several introns. Sequence analysis of the MRF1 gene revealed that it encodes a protein highly similar to prokaryotic peptide chain release factors, especially RF-1. Disruption of the gene results in a high instability of the mitochondrial genome, a hallmark for a strict lesion in mitochondrial protein synthesis. The respiratory negative phenotype of mrf1 mutants lacking all known mitochondrial introns and the reduced synthesis of mitochondrial translation products encoded by unsplit genes confirm a primary defect in mitochondrial protein synthesis. Over-expression of the MRF1 gene in a mitochondrial nonsense suppressor strain reduces suppression in a dosage-dependent manner, shedding new light on the role of the '530 region' of 16S-like ribosomal RNA in translational fidelity.

| S-EPMC334525 | biostudies-other

Peptide chain release factor DIG8 regulates plant growth by affecting ROS-mediated sugar transportation in <i>Arabidopsis thaliana</i>.

Project description:Chloroplasts have important roles in photosynthesis, stress sensing and retrograde signaling. However, the relationship between chloroplast peptide chain release factor and ROS-mediated plant growth is still unclear. In the present study, we obtained a loss-of-function mutant dig8 by EMS mutation. The dig8 mutant has few lateral roots and a pale green leaf phenotype. By map-based cloning, the DIG8 gene was located on AT3G62910, with a point mutation leading to amino acid substitution in functional release factor domain. Using yeast-two-hybrid and BiFC, we confirmed DIG8 protein was characterized locating in chloroplast by co-localization with plastid marker and interacting with ribosome-related proteins. Through observing by transmission electron microscopy, quantifying ROS content and measuring the transport efficiency of plasmodesmata in dig8 mutant, we found that abnormal thylakoid stack formation and chloroplast dysfunction in the dig8 mutant caused increased ROS activity leading to callose deposition and lower PD permeability. A local sugar supplement partially alleviated the growth retardation phenotype of the mutant. These findings shed light on chloroplast peptide chain release factor-affected plant growth by ROS stress.

| S-EPMC10102589 | biostudies-literature

A dominant mutation in the gene encoding the erythroid transcription factor KLF1 causes a congenital dyserythropoietic anemia.

Project description:The congenital dyserythropoietic anemias (CDAs) are inherited red blood cell disorders whose hallmarks are ineffective erythropoiesis, hemolysis, and morphological abnormalities of erythroblasts in bone marrow. We have identified a missense mutation in KLF1 of patients with a hitherto unclassified CDA. KLF1 is an erythroid transcription factor, and extensive studies in mouse models have shown that it plays a critical role in the expression of globin genes, but also in the expression of a wide spectrum of genes potentially essential for erythropoiesis. The unique features of this CDA confirm the key role of KLF1 during human erythroid differentiation. Furthermore, we show that the mutation has a dominant-negative effect on KLF1 transcriptional activity and unexpectedly abolishes the expression of the water channel AQP1 and the adhesion molecule CD44. Thus, the study of this disease-causing mutation in KLF1 provides further insights into the roles of this transcription factor during erythropoiesis in humans.

| S-EPMC2978953 | biostudies-literature

Cloning and expression of a mammalian peptide chain release factor with sequence similarity to tryptophanyl-tRNA synthetases.

Project description:The termination of protein synthesis is encoded by in-frame nonsense (stop) codons. Most organisms use three nonsense codons: UGA, UAG, and UAA. In contrast to sense codons, which are decoded by specific tRNAs, nonsense codons are decoded by proteins called release factors (RFs). Here we report the cloning of a mammalian RF cDNA by the use of monoclonal antibodies specific for rabbit RF. Functional studies showed that, when expressed in Escherichia coli, the protein encoded by this cDNA has in vitro biochemical characteristics similar to those of previously characterized mammalian RFs. DNA sequencing of this eukaryotic RF cDNA revealed a remarkable sequence similarity to bacterial and mitochondrial tryptophanyl-tRNA synthetases, with the greatest similarity confined to the synthetase active site, and no obvious similarity to bacterial RFs.

| S-EPMC53930 | biostudies-other

Vitellogenin gene expression in autogenous Culex tarsalis.

Project description:Autogeny, the ability of a mosquito to mature an initial batch of eggs without blood feeding, is an alternative reproductive strategy with important implications for vector-borne disease transmission. Regulation of the major yolk protein (vitellogenin; Vg) genes during bloodmeal-induced oogenesis is well studied, but little is known about regulation of vitellogenesis in autogenous mosquitoes. We characterized the expression of four vitellogenin genes (Vg1a, Vg1b, Vg2a and Vg2b) in an autogenous strain of the West Nile Virus vector, Culex tarsalis. All vitellogenin genes were expressed during autogenous reproduction and following a bloodmeal, although the intensity and duration of expression varied amongst genes. Quantitative PCR analysis of vitellogenin transcription during autogeny revealed a similar temporal pattern to known vitellogenin expression profiles in anautogenous Aedes aegypti. Vitellogenin transcript, primarily produced from the Vg1b gene, was also detected in the larval and pupal stages of development, but no detectable vitellogenin protein was produced during this time period.

| S-EPMC2907424 | biostudies-literature

Primary ciliary dyskinesia caused by homozygous mutation in DNAL1, encoding dynein light chain 1.

Project description:In primary ciliary dyskinesia (PCD), genetic defects affecting motility of cilia and flagella cause chronic destructive airway disease, randomization of left-right body asymmetry, and, frequently, male infertility. The most frequent defects involve outer and inner dynein arms (ODAs and IDAs) that are large multiprotein complexes responsible for cilia-beat generation and regulation, respectively. Although it has long been suspected that mutations in DNAL1 encoding the ODA light chain1 might cause PCD such mutations were not found. We demonstrate here that a homozygous point mutation in this gene is associated with PCD with absent or markedly shortened ODA. The mutation (NM_031427.3: c.449A>G; p.Asn150Ser) changes the Asn at position150, which is critical for the proper tight turn between the ? strand and the ? helix of the leucine-rich repeat in the hydrophobic face that connects to the dynein heavy chain. The mutation reduces the stability of the axonemal dynein light chain 1 and damages its interactions with dynein heavy chain and with tubulin. This study adds another important component to understanding the types of mutations that cause PCD and provides clinical information regarding a specific mutation in a gene not yet known to be associated with PCD.

| S-EPMC3146731 | biostudies-literature

Localization and characterization of the gene encoding release factor RF3 in Escherichia coli.

Project description:Two protein release factors (RFs) showing codon specificity, RF1 and RF2, are known to be required for polypeptide chain termination in Escherichia coli. A third protein component has also been described that stimulates termination in vitro, but it has remained uncertain whether this protein, RF3, participates in termination in vivo or is essential to cell growth. We report (i) the purification and N-terminal sequencing of RF3; (ii) the isolation of transposon insertion mutants similar to miaD, a suppressor of a leaky UAA mutation affecting the gene miaA, leading to enhanced nonsense suppression; (iii) the localization of the affected gene on the physical map of the chromosome; and (iv) the cloning and sequencing of the wild-type gene, providing proof that it encodes the factor RF3. We designate the gene prfC. Two transposon insertions were shown to interrupt the coding sequence of prfC, at codons 287 and 426. The enhanced nonsense suppression in the insertion mutants shows that the product participates in termination in vivo. The isolation of such mutants strongly suggests that the gene product is not essential to cell viability, though cell growth is affected. RF3 is a protein with a molecular weight of 59,460 containing 528 amino acids and displays much similarity to elongation factor EF-G, a GTP binding protein necessary for ribosomal translocation, and other GTP binding proteins known or thought to interact with the ribosome.

| S-EPMC44094 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data