Search results for "Nonsense"

Gene-based treatment options for Usher type 1C by translational read-through of a nonsense mutation

2012

The Usher syndrome (USH) is the most frequent cause of inherited combined deaf-blindness. The ciliopathy is clinically and genetically heterogeneous, assigned to three clinical USH types of which the most severe type is USH1. The USH1C gene encodes the PDZ containing scaffold protein harmonin which is expressed in form of numerous alternatively spliced variants. Hamonin binds directly to all USH1/2 proteins and is a key organizer of USH protein networks in photoreceptor cells. So far no effective treatment for the ophthalmic component of USH exists. Translational read-through was introduced as an innovative therapy option for several non-ocular diseases caused by nonsense mutations leading …

Optimization of a new lead promoting the readthrough of the nonsense mutations for CFTR rescue in human CF cells

2017

Optimization of a new lead promoting the readthrough of the nonsense mutations for CFTR rescue in human CF cells Laura Lentini, Raffaella Melfi, Sara Baldassano, Marco Tutone, Aldo Di Leonardo, Andrea Pace, Ivana Pibiri Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo Background and rationale Cystic Fibrosis patients with nonsense mutations in the CFTR gene have a more severe form of the disease. Nonsense mutations represent about 10% of the mutations that affect the CFTR gene and they are frequently associated to the classical F508 mutation (1). A potential treatment for this genetic alteration is to promote the translationa…

PTC124 derivatives as a novel approach to improve the readthrough of premature stop codons in the CFTR gene.

2011

Background Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). Approximately 10% (worldwide) of patients have in-frame nonsense mutations (UAA, UAG or UGA class I mutations) in the CF trans-membrane regulator (CFTR) gene that result in premature stop codons (PTCs) in the messenger RNA (mRNA) generating truncated CFTR protein responsible for a severe CF phenotype. Pharmacological approaches have been proposed to directly overcome PTCs. Ataluren (PTC124) a small molecule that mimics the activity of aminoglycosides has been suggested to allow PTCs readthrough and to partially restore the protein function. However, des…

Translational readthrough inducing drugs: a study of toxicity in mice models and in vitro safety validation of the specific readthrough process.

2022

Objective Nonsense mutations are responsible for 15% of Cystic Fibrosis (CF) patients due to the introduction of a premature stop codon (PTC) in the mRNA and the production of a truncated CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) protein1. A promising therapeutic approach for stop mutations is the suppression therapy by Translational Readthrough Inducing Drugs (TRIDs) to restore the expression of the protein2,3. Recently three new TRIDS (NV848, NV914, NV930) have been proposed and validated by several assays. Our work was focused on TRIDs NV848, NV914, NV930. Important aspects of TRIDs to be evaluated are their specificity towards PTC, to demonstrate that TRIDs do not inter…

X CONVENTION OF INVESTIGATORS IN CYSTIC FIBROSIS.

2012

Background Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). Approximately 10% (worldwide) of patients have in-frame nonsense mutations (UAA, UAG or UGA class I mutations) in the CF trans-membrane regulator (CFTR) gene that result in premature stop codons (PTCs) in the messenger RNA (mRNA) generating truncated CFTR protein responsible for a severe CF phenotype. Pharmacological approaches have been proposed to directly overcome PTCs. Ataluren (PTC124) a small molecule that mimics the activity of aminoglycosides has been suggested to allow PTCs readthrough and to partially restore the protein function. However, des…

The innovative role of the readthrough inducing drugs in the translation rescue of mRNAs characterized by premature stop codon (PTCs).

RNA quality control: RppH activity allows selective removal of nonsense messages in E. coli.

2009

Polar effect, the reduced expression level of sequences downstream to mutations reducing translation efficiency, is usually due to transcription termination or inefficient translation reinitiation. Untranslated mRNAs are known to be quickly degraded, probably because of their increased accessibility to degradative enzymes due to the absence of translating ribosomes. In III-VI-I operon of phage f1, a strong polar effect is observed in a gIII 5’ proximal nonsense mutant, resulting in a very fast, RNaseE mediated, degradation of any full-length mRNA. RNaseE is a key component of the E. coli degradosome, the major RNA processing/degrading machinery. Its endonucleolytic activity is strongly enha…

Missense and nonsense mutations in melanocortin 1 receptor (MC1R) gene of different goat breeds: association with red and black coat colour phenotype…

2009

Abstract Background Agouti and Extension loci control the relative amount of eumelanin and pheomelanin production in melanocytes that, in turn, affects pigmentation of skin and hair. The Extension locus encodes the melanocortin 1 receptor (MC1R) whose permanent activation, caused by functional mutations, results in black coat colour, whereas other inactivating mutations cause red coat colour in different mammals. Results The whole coding region of the MC1R gene was sequenced in goats of six different breeds showing different coat colours (Girgentana, white cream with usually small red spots in the face; Maltese, white with black cheeks and ears; Derivata di Siria, solid red; Murciano-Granad…

The Molecular Basis of X-Linked Spondyloepiphyseal Dysplasia Tarda

2001

The X-linked form of spondyloepiphyseal dysplasia tarda (SEDL), a radiologically distinct skeletal dysplasia affecting the vertebrae and epiphyses, is caused by mutations in the SEDL gene. To characterize the molecular basis for SEDL, we have identified the spectrum of SEDL mutations in 30 of 36 unrelated cases of X-linked SEDL ascertained from different ethnic populations. Twenty-one different disease-associated mutations now have been identified throughout the SEDL gene. These include nonsense mutations in exons 4 and 5, missense mutations in exons 4 and 6, small (2–7 bp) and large (>1 kb) deletions, insertions, and putative splicing errors, with one splicing error due to a complex deleti…

WWOX-related encephalopathies: delineation of the phenotypical spectrum and emerging genotype-phenotype correlation

2014

International audience; BACKGROUND:Homozygous mutations in WWOX were reported in eight individuals of two families with autosomal recessive spinocerebellar ataxia type 12 and in two siblings with infantile epileptic encephalopathy (IEE), including one who deceased prior to DNA sampling.METHODS:By combining array comparative genomic hybridisation, targeted Sanger sequencing and next generation sequencing, we identified five further patients from four families with IEE due to biallelic alterations of WWOX.RESULTS:We identified eight deleterious WWOX alleles consisting in four deletions, a four base-pair frameshifting deletion, one missense and two nonsense mutations. Genotype-phenotype correl…