A new point mutation in the gene coding for strong phosphine resistance inTribolium castaneum(Coleoptera: Tenebrionidae)

2016 ◽  
Author(s):  
Zhaorigetu Chen
Keyword(s):  
Point Mutation ◽  
Gene Coding ◽  
Phosphine Resistance ◽  
Coleoptera Tenebrionidae

scholarly journals Altered toxicity of the prion protein peptide PrP106–126 carrying the Ala117→Val mutation

2000 ◽  
Vol 346 (3) ◽  
pp. 785-791 ◽  
Author(s):  
David R. BROWN
Keyword(s):  
Point Mutation ◽  
Prion Protein ◽  
Prion Diseases ◽  
Point Mutations ◽  
Human Sequence ◽  
Gene Coding ◽  
Normal Human ◽  
Microtubule Formation ◽  
Β Sheet ◽  
Prion Protein Peptide

The inherited prion diseases such as Gerstmann-Sträussler-Scheinker syndrome (GSS) are linked to point mutations in the gene coding for the cellular isoform of the prion protein (PrPC). One particular point mutation A117V (Ala117 → Val) is linked to a variable pathology that usually includes deposition of neurofibrillary tangles. A prion protein peptide carrying this point mutation [PrP106-126(117V)] was generated and compared with a peptide based on the normal human sequence [PrP106-126(117A)]. The inclusion of this point mutation increased the toxicity of PrP106-126 which could be linked to an increased β-sheet content. An assay of microtubule formation in the presence of tau indicated that PrP106-126 decreased the rate of microtubule formation that could be related to the displacement of tau. PrP106-126 carrying the 117 mutation was more efficient at inhibiting microtubule formation. These results suggest a possible mechanism of toxicity for protein carrying this mutation via destabilization of the cytoskeleton and deposition of tau in filaments, as observed in GSS.

scholarly journals Genetic basis for clarithromycin resistance among isolates of Mycobacterium chelonae and Mycobacterium abscessus.

1996 ◽  
Vol 40 (7) ◽  
pp. 1676-1681 ◽  
Author(s):  
R J Wallace ◽  
A Meier ◽  
B A Brown ◽  
Y Zhang ◽  
P Sander ◽  
...  
Keyword(s):  
Point Mutation ◽  
Random Amplified Polymorphic Dna ◽  
Mycobacterium Abscessus ◽  
Single Step ◽  
23S Rrna ◽  
Mycobacterium Chelonae ◽  
Clarithromycin Resistance ◽  
Gene Coding ◽  
Disseminated Disease ◽  
Dna Pcr

Resistance to clarithromycin among isolates of Mycobacterium chelonae and M. abscessus was observed in 18 of 800 (2.3%) patients tested between 1990 and 1995. Patients whose isolates were resistant had either disseminated disease or chronic lung disease, and the resistant isolates were recovered after clarithromycin monotherapy. Sequencing of the gene coding for the 23S rRNA peptidyltransferase region revealed a point mutation involving adenine at position 2058 (38%) or adenine at position 2059 (62%) in 20 of 20 relapse isolates from the first 13 patients identified. By pulsed-field gel electrophoresis or random amplified polymorphic DNA PCR, initial and relapse isolates were shown to have identical DNA patterns. M. chelonae and M. abscessus isolates were found to have only a single chromosomal copy of the rRNA operon, thus making them susceptible to single-step mutations. Thus, clarithromycin resistance in these species of rapidly growing mycobacteria relates to a point mutation in the gene coding for 23S rRNA and occurs in limited clinical situations, but was identified in almost 5% of isolates tested in 1995.

scholarly journals Molecular defect in coagulation factor XFriuli results from a substitution of serine for proline at position 343

Blood ◽  
1991 ◽  
Vol 77 (2) ◽  
pp. 317-323 ◽  
Author(s):  
HL James ◽  
A Girolami ◽  
DS Fair
Keyword(s):  
Point Mutation ◽  
Serine Proteases ◽  
Direct Sequencing ◽  
Coagulation Factor ◽  
Amino Acid Position ◽  
Molecular Defect ◽  
Nucleotide Position ◽  
Factor X ◽  
Gene Coding ◽  
X Gene

Abstract Our previous findings suggested that coagulation factor XFriuli could be functionally defective owing to a point mutation in the portion of the factor X gene coding for the fully activated heavy chain. To verify the existence of this postulated change, we analyzed all eight exons of the normal and Friuli factor X gene. Each exon was amplified from genomic DNA using the polymerase chain reaction and cloned into the plasmid pUC19. The amplified DNA inserts were subjected to direct sequencing by the dideoxy chain termination method with forward and reverse oligonucleotide sequencing primers. A point mutation (C to T transition at nucleotide position 19,297) that results in coding for serine (TCC) in place of proline (CCC) at amino acid position 343 was found. This substitution involves a highly conserved proline residue oriented spatially close to both the cleavage site of the zymogen and the active site of the enzyme and explains the previous observations of discrete biochemical and functional differences between factor XFriuli and normal factor X. The mutation abolished an HgiCI restriction site present in the normal factor X gene, and this change constitutes the basis for a convenient method for screening individuals carrying this molecular defect. Proline343 is in conserved region 5 of the serine protease superfamily to which factor X belongs and is part of a 14- residue L*****P******C motif that occurs in at least 16 other enzymes. Computer analysis suggests that the motif may be an essential aspect of conformational features important to functional properties of factor X as well as other serine proteases.

scholarly journals Evaluation of Knockdown Bioassay Methods to Assess Phosphine Resistance in the Red Flour Beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 140 ◽  
Author(s):  
Aaron Cato ◽  
Edwin Afful ◽  
Manoj K. Nayak ◽  
Thomas W. Phillips
Keyword(s):  
Tribolium Castaneum ◽  
Glass Tube ◽  
Red Flour Beetle ◽  
High Concentration ◽  
Flour Beetle ◽  
Phosphine Resistance ◽  
Gas Tight ◽  
Weak Resistance ◽  
Coleoptera Tenebrionidae

Resistance to the fumigant phosphine in Tribolium castaneum occurs worldwide. This study evaluated tests based on adult knockdown time, the time for a beetle to become immobile, when exposed to a high concentration of phosphine. We recorded knockdown times of beetles that remained completely still for 30 s when exposed to 3000 ppm of phosphine in a large, gas-tight glass tube. Beetles were used from 12 populations, of which six were ‘susceptible’ to phosphine, three were ‘weakly resistant’, and three were ‘strongly resistant’. Knockdown times were determined for single beetles, as well as for groups of ten beetles for which the time to knockdown for either five beetles (KT50) or ten beetles (KT100) were recorded. Similar knockdown times occurred across susceptible and resistant populations. However, the KT100 tests generated conservative times for diagnosing strong vs. weak resistance. The strong resistant populations were all over 100 min with KT100, compared to 60 min or less for susceptible and weak resistant populations. Special tests on single beetles revealed higher knockdown times in insects that were deliberately disturbed compared to those without any disturbances. Work reported here suggests a knockdown test conducted on beetles in a matter of minutes or hours could help classify phosphine resistance status prior to decisions on phosphine fumigation.

scholarly journals Molecular defect in coagulation factor XFriuli results from a substitution of serine for proline at position 343

Blood ◽  
1991 ◽  
Vol 77 (2) ◽  
pp. 317-323
Author(s):  
HL James ◽  
A Girolami ◽  
DS Fair
Keyword(s):  
Point Mutation ◽  
Serine Proteases ◽  
Direct Sequencing ◽  
Coagulation Factor ◽  
Amino Acid Position ◽  
Molecular Defect ◽  
Nucleotide Position ◽  
Factor X ◽  
Gene Coding ◽  
X Gene

Our previous findings suggested that coagulation factor XFriuli could be functionally defective owing to a point mutation in the portion of the factor X gene coding for the fully activated heavy chain. To verify the existence of this postulated change, we analyzed all eight exons of the normal and Friuli factor X gene. Each exon was amplified from genomic DNA using the polymerase chain reaction and cloned into the plasmid pUC19. The amplified DNA inserts were subjected to direct sequencing by the dideoxy chain termination method with forward and reverse oligonucleotide sequencing primers. A point mutation (C to T transition at nucleotide position 19,297) that results in coding for serine (TCC) in place of proline (CCC) at amino acid position 343 was found. This substitution involves a highly conserved proline residue oriented spatially close to both the cleavage site of the zymogen and the active site of the enzyme and explains the previous observations of discrete biochemical and functional differences between factor XFriuli and normal factor X. The mutation abolished an HgiCI restriction site present in the normal factor X gene, and this change constitutes the basis for a convenient method for screening individuals carrying this molecular defect. Proline343 is in conserved region 5 of the serine protease superfamily to which factor X belongs and is part of a 14- residue L*****P******C motif that occurs in at least 16 other enzymes. Computer analysis suggests that the motif may be an essential aspect of conformational features important to functional properties of factor X as well as other serine proteases.

Sign in / Sign up

Export Citation Format

Share Document