scholarly journals mRNA Analysis of Frameshift Mutations with Stop Codon in the Last Exon: The Case of Hemoglobins Campania [α1 cod95 (−C)] and Sciacca [α1 cod109 (−C)]

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1390
Author(s):  
Giovanna Cardiero ◽  
Gennaro Musollino ◽  
Romeo Prezioso ◽  
Giuseppina Lacerra
Keyword(s):  
Stop Codon ◽  
Globin Gene ◽  
In Silico Analysis ◽  
Premature Termination Codon ◽  
Protein Variant ◽  
Structure Variation ◽  
Dominant Phenotype ◽  
Mrna Variants ◽  
Hemoglobin Variants ◽  
Few Data

An insertion or deletion of a nucleotide (nt) in the penultimate or the last exon can result in a frameshift and premature termination codon (PTC), giving rise to an unstable protein variant, showing a dominant phenotype. We described two α-globin mutants created by the deletion of a nucleotide in the penultimate or the last exon of the α1-globin gene: the Hb Campania or α1 cod95 (−C), causing a frameshift resulting in a PTC at codon 102, and the Hb Sciacca or α1 cod109 (−C), causing a frameshift and formation of a PTC at codon 133. The carriers showed α-thalassemia alterations (mild microcytosis with normal Hb A2) and lacked hemoglobin variants. The 3D model indicated the α-chain variants’ instability, due to the severe structural alterations with impairment of the chaperone alpha-hemoglobin stabilizing protein (AHSP) interaction. The qualitative and semiquantitative analyses of the α1mRNA from the reticulocytes of carriers highlighted a reduction in the variant cDNAs that constituted 34% (Hb Campania) and 15% (Hb Sciacca) of the total α1-globin cDNA, respectively. We developed a workflow for the in silico analysis of mechanisms triggering no-go decay, and its results suggested that the reduction in the variant mRNA was likely due to no-go decay caused by the presence of a rare triplet, and, in the case of Hb Sciacca, also by the mRNA’s secondary structure variation. It would be interesting to correlate the phenotype with the quantity of other frameshift mRNA variants, but very few data concerning α- and β-globin variants are available.

Hemoglobin variants, hematological parameters andβ-globin gene cluster haplotypes in an isolated Amerindian group from the Orinoco River Delta

2008 ◽  
Vol 35 (2) ◽  
pp. 250-255 ◽  
Author(s):  
Anabel Arends ◽  
Marycarmen Chacín ◽  
Martha Bravo-Urquiola ◽  
Tibisay Arends De O ◽  
Maritza Álvarez ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Hematological Parameters ◽  
Globin Gene ◽  
River Delta ◽  
Orinoco River ◽  
Globin Gene Cluster ◽  
Hemoglobin Variants

scholarly journals An Alcohol Dehydrogenase 3 (ADH3) from Entamoeba histolytica Is Involved in the Detoxification of Toxic Aldehydes

2020 ◽  
Vol 8 (10) ◽  
pp. 1608
Author(s):  
Constantin König ◽  
Martin Meyer ◽  
Corinna Lender ◽  
Sarah Nehls ◽  
Tina Wallaschkowski ◽  
...  
Keyword(s):  
Alcohol Dehydrogenase ◽  
Entamoeba Histolytica ◽  
Biochemical Characterization ◽  
Stop Codon ◽  
In Silico Analysis ◽  
Peptidase Activity ◽  
Stool Samples ◽  
Human Stool

Recently, a putative alcohol dehydrogenase 3, termed EhADH3B of the Entamoeba histolytica isolate HM-1:IMSS was identified, which is expressed at higher levels in non-pathogenic than in pathogenic amoebae and whose overexpression reduces the virulence of pathogenic amoebae. In an in silico analysis performed in this study, we assigned EhADH3B to a four-member ADH3 family, with ehadh3b present as a duplicate (ehadh3ba/ehadh3bb). In long-term laboratory cultures a mutation was identified at position 496 of ehadh3ba, which codes for a stop codon, which was not the case for amoebae isolated from human stool samples. When using transfectants that overexpress or silence ehadh3bb, we found no or little effect on growth, size, erythrophagocytosis, motility, hemolytic or cysteine peptidase activity. Biochemical characterization of the recombinant EhADH3Bb revealed that this protein forms a dimer containing Ni2+ or Zn2+ as a co-factor and that the enzyme converts acetaldehyde and formaldehyde in the presence of NADPH. A catalytic activity based on alcohols as substrates was not detected. Based on the results, we postulate that EhADH3Bb can reduce free acetaldehyde released by hydrolysis from bifunctional acetaldehyde/alcohol dehydrogenase-bound thiohemiacetal and that it is involved in detoxification of toxic aldehydes produced by the host or the gut microbiota.

scholarly journals Clinical and genetic heterogeneity in black patients with homozygous beta-thalassemia from the southeastern United States

Blood ◽  
1988 ◽  
Vol 72 (3) ◽  
pp. 1007-1014 ◽  
Author(s):  
JM Gonzalez-Redondo ◽  
TA Stoming ◽  
KD Lanclos ◽  
YC Gu ◽  
A Kutlar ◽  
...  
Keyword(s):  
South Carolina ◽  
Genomic Dna ◽  
Stop Codon ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Nucleotide Substitutions ◽  
Taq Polymerase ◽  
Black Patients ◽  
Codon 61

Abstract The presence of various substitutions and deletions resulting in beta- thalassemia was studied in 19 black patients with homozygous beta- thalassemia and in numerous relatives; all patients were from Georgia, South Carolina, and Alabama. Methodology included gene mapping, amplification of genomic DNA with Taq polymerase, identification of known nucleotide substitutions or a single nucleotide deletion through hybridization with synthetic oligonucleotides, cloning and sequencing of a beta-globin gene, and sequencing of amplified genomic DNA. Of the 38 chromosomes tested, 21 (55%) had the A----G substitution at nt -29, eight (21%) had the C----T substitution at nt -88, three (8%) had the substitution at codon 24, while one each of the following abnormalities were also detected: frameshift at codon 6, a C----A mutation at nt 848 of the beta IVS-II (new), an A----T mutation at codon 61 (new), a deletion of 1.35 kilobases including the 5′ end of beta, a Ggamma(Agammadelta beta) degree-thalassemia, and one thalassemia determinant that remained unidentified. The C----A mutation at nt 848 of IVS-II occurred at a position 3 nucleotides 5′ to the third exon, adjacent to the invariant AG dinucleotide of the acceptor sequence. The A----T mutation in codon 61 (AAG----TAG) resulted in the creation of a stop codon and thus in beta degree-thalassemia. The various mutations occurred on chromosomes with different haplotypes; however, chromosomes with a specific mutation but with different haplotypes belonged to one specific framework, which suggested that crossovers were responsible for these different types. Hemoglobin (Hb) F levels were generally high (55% to 75% with 98.5% in one patient with beta degree/beta degree); a few patients with specific haplotypes and an alpha-thalassemia-2 heterozygosity had a lower Hb F level. The Ggamma in the Hb F was consistently high when the C----T mutation occurred at nt -158 to the Cap site of the Ggamma-globin gene; seven patients with +/+ at this site had an average Ggamma of 73.8%, eight patients with +/- had 64.8%, and one patient with -/- had 34.2%. Variations in hematologic values and in Hb F, Ggamma, and Hb A2 levels of relatives with a beta- thalassemia heterozygosity depended to some extent on the types of mutations or deletions and on the haplotypes of the chromosomes with the beta-thalassemia determinant.

A Novel β Globin Gene Mutation, Reported As An α Chain Hemoglobin Variant By High Performance Liquid Chromatography (HPLC) & As Sickle Cell Trait On New Born Screening: A case Report

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 954-954
Author(s):  
Kranthi Nandan Seelaboyina ◽  
Jennifer Alison Busse ◽  
Sandeep Malik ◽  
Thomas Moulton
Keyword(s):  
Sickle Cell ◽  
Copy Number ◽  
Sickle Cell Trait ◽  
Globin Gene ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Thalassemia Intermedia ◽  
Exon 2 ◽  
Alpha Globin ◽  
Hemoglobin Variants

Abstract Introduction There are 827 variants of β thalassemia reported to the registry of human hemoglobin variants and thalassemias registry 1. Genetic mutations of β thalassemia are very diverse but can be broadly divided in to non deletion forms and deletion forms. The new mutation is a frame shift insertion in exon 2 of the β globin gene. To the best of our knowledge this mutation has never been described before and presents as a mild form β thalassemia intermedia. Objective To describe the phenotypic presentation of the new β globin variant, due to insertion of 9 nucleotides (AAAGTGCTC) between nucleotides c.207 and c.208. Case report A 22 months-old Hispanic boy who was referred for evaluation of persistent anemia. The new born screening for the child was positive for sickle cell trait. Initial hemoglobin (Hb) was 8.8, hematocrit was 27 and MCV was 65.5, which were decreased. RDW was 25.2, which was increased. Hemoglobin evaluation by acid and alkaline electrophoresis and HPLC revealed a HbS 0%, HbF 6.5% HbA 78.4%, HbA2 4.9% and a Hb variant 10.2%. The interpretation of the results was an α globin variant suggestive of Hb Montefiore and β thalassemia trait. Alpha thalassemia PCR for the 7 most common deletions in the α globin chain was negative. Subsequent α globin gene sequencing revealed no α globin gene mutations. On physical exam there were no bony changes or hepatosplenomegaly. Family History The mother is 29-year-old with HbAA. The father is 39-years-old with the same mutation on beta globin gene analysis. Hb electrophoresis also suggested an α and β globin mutation. Alpha thalassemia PCR was negative and he had a normal α globin gene copy number. At age 19 he had a splenectomy secondary to splenomegaly and hypersplenism. He is consistently anemic with Hb< 9 and MCV < 70. The child has a paternal half brother, who is 21 years old and has similar problems as father. He had a splenectomy at the age of 17 after admission for abdominal pain. The patient has a 5-year-old sibling, who is normal with HbAA and another paternal half sibling reported as no anemia. Discussion Though β thalassemia intermedia is most commonly homozygous or compound heterozygous, less frequently it can be due to single locus mutation. DNA sequencing of the α globin gene of the index case was completely normal and there was normal copy number of the α globin gene in the father. No Hb S was found on Hb electrophoresis. The new mutation adds 9 base pairs to exon 2 and 3 amino acids (Lys-Val-Leu) between amino acid 68 and 69 of the protein. This elongates the beta chain which can lead to instability and precipitation of Hb as well as hemolysis and anemia2. Further studies like short time incubation and pulse chase globin chain synthesis experiments are needed to know the stability of the β globin protein3. In addition, an increase of α globin gene copy number can also be a reason for increasing the severity of β thalassemia trait2. However the α gene copy was normal in the father. Conclusion We present a case of a child with a false positive abnormal newborn screen suggestive of sickle cell trait, as well as a Hb electrophoresis suggestive of an alpha globin mutation. As the father and paternal brother have had a splenectomy in their teen years with noted hepatosplenomegaly, suggestive of increased hemolysis, and the anemia is more severe than usual for β thalassemia trait, this suggests that phenotypically the c.199_207dup variant presents as a mild β thalassemia intermedia. In addition, there does not seem to be any bony abnormalities associated with marrow hyperplasia. As both our patients are heterozygous for this novel mutation with normal α globin gene copy number and alpha globin sequencing, we suspect that elongation of the β globin produces an unstable hemoglobin with a mild β thalassemia intermedia phenotype2. References 1. Databases of human hemoglobin variants and other resources at the globin gene server. Hemoglobin. 25(2):183-93, 2001 May. 2. Galanello R, Cao A. Relationship between genotype and phenotype. Thalassemia intermedia. Annals of the New York Academy of Sciences 1998; 850:325-33. 3. Is hemoglobin instability important in the interaction between hemoglobin E and beta thalassemia? Blood September 15, 1998 vol. 92 no. 6 2141-2146. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Identification of a recently evolved goat embryonic beta-globin pseudogene which retains transcriptional activity in vitro.

1984 ◽  
Vol 4 (10) ◽  
pp. 2120-2127 ◽  
Author(s):  
S G Shapiro ◽  
J B Lingrel
Keyword(s):  
Transcriptional Activity ◽  
Stop Codon ◽  
Globin Gene ◽  
Consensus Sequence ◽  
Duplication Event ◽  
Beta Globin ◽  
Gene Sets ◽  
Sequence Elements ◽  
Group 5

A clone containing the entire goat epsilon V beta-globin gene, which lies downstream from the two tandemly duplicated four-gene sets containing the beta C and beta A genes in the linkage group 5'-epsilon I-epsilon II-psi beta X-beta C-epsilon III-epsilon IV-psi beta Z-beta A-epsilon V-3', was isolated, and the sequence of the gene was determined. epsilon V is most homologous to the first gene in each of these sets, epsilon I and epsilon III, and appears to be a third duplicated copy of these genes, possibly the first gene in a third four-gene set. Homology of epsilon V to epsilon I is very high (93.2%) in coding regions, and all transcription, processing, and potential translation consensus sequence elements appear to be present, although the Hogness box of epsilon V is altered compared with that of epsilon I by the deletion of an A(AATAAAA----AATAAA). Nevertheless, epsilon V is clearly a pseudogene as a result of two deletions and one insertion (or insertion-deletion) in its coding sequence, the first of which produces an in-frame stop codon at amino acid 54. Unlike the more highly mutated goat beta-like pseudogene duplicates psi beta X and psi beta Z, epsilon V acquired its defects after the duplication event in which it was created. Its recently acquired defects have left the epsilon V promoter sufficiently conserved to retain transcriptional activity in vitro. The acquisition of defects by this gene may be related to the multiple gene duplications which have created at least five epsilon type genes in the goat beta-globin locus.

Analysis of ZP1 gene reveals differences in zona pellucida composition in carnivores

2018 ◽  
Vol 30 (2) ◽  
pp. 272 ◽  
Author(s):  
C. Moros-Nicolás ◽  
A. Leza ◽  
P. Chevret ◽  
A. Guillén-Martínez ◽  
L. González-Brusi ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
In Silico ◽  
Polar Bear ◽  
Acrosome Reaction ◽  
Stop Codon ◽  
In Silico Analysis ◽  
Weddell Seal ◽  
Fur Seal ◽  
The Antarctic ◽  
Silico Analysis

The zona pellucida (ZP) is an extracellular envelope that surrounds mammalian oocytes. This coat participates in the interaction between gametes, induction of the acrosome reaction, block of polyspermy and protection of the oviductal embryo. Previous studies suggested that carnivore ZP was formed by three glycoproteins (ZP2, ZP3 and ZP4), with ZP1 being a pseudogene. However, a recent study in the cat found that all four proteins were expressed. In the present study, in silico and molecular analyses were performed in several carnivores to clarify the ZP composition in this order of mammals. The in silico analysis demonstrated the presence of the ZP1 gene in five carnivores: cheetah, panda, polar bear, tiger and walrus, whereas in the Antarctic fur seal and the Weddell seal there was evidence of pseudogenisation. Molecular analysis showed the presence of four ZP transcripts in ferret ovaries (ZP1, ZP2, ZP3 and ZP4) and three in fox ovaries (ZP2, ZP3 and ZP4). Analysis of the fox ZP1 gene showed the presence of a stop codon. The results strongly suggest that all four ZP genes are expressed in most carnivores, whereas ZP1 pseudogenisation seems to have independently affected three families (Canidae, Otariidae and Phocidae) of the carnivore tree.

HbVar: A relational database of human hemoglobin variants and thalassemia mutations at the globin gene server

2002 ◽  
Vol 19 (3) ◽  
pp. 225-233 ◽  
Author(s):  
Ross C. Hardison ◽  
David H.K. Chui ◽  
Belinda Giardine ◽  
Cathy Riemer ◽  
George P. Patrinos ◽  
...  
Keyword(s):  
Relational Database ◽  
Globin Gene ◽  
Human Hemoglobin ◽  
Hemoglobin Variants

scholarly journals Alternative REST Splicing Underappreciated

2017 ◽  
Author(s):  
Guo-Lin Chen ◽  
Gregory M. Miller
Keyword(s):  
Alternative Splicing ◽  
Stop Codon ◽  
Premature Stop Codon ◽  
Protein Isoforms ◽  
Multiple Protein ◽  
Mrna Variants ◽  
Cellular Context ◽  
Active Transcription ◽  
Context Dependent ◽  
Ageing Brain

As a major orchestrator of the cellular epigenome, the repressor element-1 silencing transcription factor (REST) can either repress or activate thousands of genes depending on cellular context, suggesting a highly context-dependent REST function tuned by environmental cues. While REST shows cell-type non-selective active transcription1, an N-terminal REST4 isoform caused by alternative splicing – inclusion of an extra exon (N3c) which introduces a premature stop codon – has been implicated in neurogenesis and tumorigenesis2-5. Recently, in line with established epigenetic regulation of pre-mRNA splicing6,7, we demonstrated that REST undergoes extensive, context-dependent alternative splicing which results in the formation of a large number of mRNA variants predictive of multiple protein isoforms8. Supported by that immunoblotting/-staining with different anti-REST antibodies yield inconsistent results, alternative splicing allows production of various structurally and functionally different REST protein isoforms in response to shifting physiological requirements, providing a reasonable explanation for the diverse, highly context-dependent REST function. However, REST isoforms might be differentially assayed or manipulated, leading to data misinterpretation and controversial findings. For example, in contrast to the proposed neurotoxicity of elevated nuclear REST in ischemia9 and Huntington’s disease10,11, Lu et al. recently reported decreased nuclear REST in Alzheimer’s disease and neuroprotection of REST in ageing brain12. Unfortunately, alternative REST splicing was largely neglected by Lu et al., making it necessary for a reevaluation of their findings.

scholarly journals Small molecule splicing modifiers with systemic HTT-lowering activity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anuradha Bhattacharyya ◽  
Christopher R. Trotta ◽  
Jana Narasimhan ◽  
Kari J. Wiedinger ◽  
Wencheng Li ◽  
...  
Keyword(s):  
Rna Splicing ◽  
Messenger Rna ◽  
Neurodegenerative Disorder ◽  
Stop Codon ◽  
Premature Termination Codon ◽  
Protein Levels ◽  
Function Mechanism ◽  
Investigational Drugs ◽  
The Central Nervous System ◽  
Orally Bioavailable

AbstractHuntington’s disease (HD) is a hereditary neurodegenerative disorder caused by expansion of cytosine-adenine-guanine (CAG) trinucleotide repeats in the huntingtin (HTT) gene. Consequently, the mutant protein is ubiquitously expressed and drives pathogenesis of HD through a toxic gain-of-function mechanism. Animal models of HD have demonstrated that reducing huntingtin (HTT) protein levels alleviates motor and neuropathological abnormalities. Investigational drugs aim to reduce HTT levels by repressing HTT transcription, stability or translation. These drugs require invasive procedures to reach the central nervous system (CNS) and do not achieve broad CNS distribution. Here, we describe the identification of orally bioavailable small molecules with broad distribution throughout the CNS, which lower HTT expression consistently throughout the CNS and periphery through selective modulation of pre-messenger RNA splicing. These compounds act by promoting the inclusion of a pseudoexon containing a premature termination codon (stop-codon psiExon), leading to HTT mRNA degradation and reduction of HTT levels.

scholarly journals Novel GANAB variants associated with polycystic liver disease

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Liyanne F. M. van de Laarschot ◽  
René H. M. te Morsche ◽  
Alexander Hoischen ◽  
Hanka Venselaar ◽  
Hennie M. Roelofs ◽  
...  
Keyword(s):  
Liver Disease ◽  
Enzymatic Activity ◽  
In Silico Analysis ◽  
Missense Variant ◽  
Premature Termination Codon ◽  
Polycystic Liver Disease ◽  
Α Subunit ◽  
Glucosidase Ii ◽  
Polycystic Liver ◽  
In Cells

Abstract Background Polycystic liver disease (PLD) is an inherited disorder characterized by numerous cysts in the liver. Autosomal dominant polycystic kidney and liver disease (ADPKD and ADPLD, respectively) have been linked to pathogenic GANAB variants. GANAB encodes the α-subunit of glucosidase II (GIIα). Here, we report the identification of novel GANAB variants in an international cohort of patients with the primary phenotype of PLD using molecular inversion probe analysis. Results Five novel GANAB variants were identified in a cohort of 625 patients with ADPKD or ADPLD. In silico analysis revealed that these variants are likely to affect functionally important domains of glucosidase II α-subunit. Missense variant c.1835G>C p.(Arg612Pro) was predicted to disrupt the structure of the active site of the protein, likely reducing its activity. Frameshift variant c.687delT p.(Asp229Glufs*60) introduces a premature termination codon predicted to have no activity. Two nonsense variants (c.2509C>T; p.(Arg837*), and c.2656C>T; p.(Arg886*)) and splice variant c.2002+1G>C, which causes aberrant pre-mRNA splicing and affecting RNA processing, result in truncated proteins and are predicted to cause abnormal binding of α- and β-subunits of glucosidase II, thus affecting its enzymatic activity. Analysis of glucosidase II subunits in cell lines shows expression of a truncated GIIα protein in cells with c.687delT, c.2509C>T, c.2656C>T, and c.2002+1G>C variants. Incomplete colocalization of the subunits was present in cells with c.687delT or c.2002+1G>C variants. Other variants showed normal distribution of GIIα protein. Conclusions We identified five novel GANAB variants associated with PLD in both ADPKD and ADPLD patients supporting a common pathway in cystogenesis. These variants may lead to decreased or complete loss of enzymatic activity of glucosidase II which makes GANAB a candidate gene to be screened in patients with an unknown genetic background.

Sign in / Sign up

Export Citation Format

Share Document