Recent amplification of triose phosphate isomerase related sequences in lettuce

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 627-635 ◽  
Author(s):  
Ilan Paran ◽  
Richard V. Kesseli ◽  
Lore Westphal ◽  
Richard W. Michelmore

A random cDNA clone was identified as distinguishing near-isogenic lines for downy mildew resistance in lettuce. The clone detected multiple restriction fragments in genomic Southern blots of lettuce. Restriction fragment length polymorphisms (RFLPs) detected by this clone mapped to separate clusters of resistance genes; therefore, these sequences were studied in a greater detail. Sequence analysis indicated that the cDNA encoded the glycolytic enzyme triose phosphate isomerase (TPI). The lettuce clone shares 85% sequence similarity at the amino acid level with TPI from maize. TPI-related sequences were mapped in lettuce using three crosses. Ten loci were distributed in six linkage groups. Possible mechanisms of amplification and dispersion were investigated. Retrotransposition was excluded, since intron five is retained in all TPI-related genomic sequences. Large scale chromosomal rearrangements were not involved, as RFLP markers flanking TPI loci were not duplicated. A high level of genomic variability was detected by the TPI clone; 37 different restriction fragments were detected in Southern hybridizations to 64 populations of lettuce including 47 cultivars of Lactuca sativa and five wild species. Species distantly related to L. sativa had few TPI loci, indicating that their amplification and dispersion were recent and had occurred after the emergence of the L. serriola complex.Key words: triose phosphate isomerase, gene duplication, lettuce.

2021 ◽  
pp. 247255522110181
Author(s):  
Andreas Vogt ◽  
Samantha L. Eicher ◽  
Tracey D. Myers ◽  
Stacy L. Hrizo ◽  
Laura L. Vollmer ◽  
...  

Triose phosphate isomerase deficiency (TPI Df) is an untreatable, childhood-onset glycolytic enzymopathy. Patients typically present with frequent infections, anemia, and muscle weakness that quickly progresses with severe neuromusclar dysfunction requiring aided mobility and often respiratory support. Life expectancy after diagnosis is typically ~5 years. There are several described pathogenic mutations that encode functional proteins; however, these proteins, which include the protein resulting from the “common” TPIE105D mutation, are unstable due to active degradation by protein quality control (PQC) pathways. Previous work has shown that elevating mutant TPI levels by genetic or pharmacological intervention can ameliorate symptoms of TPI Df in fruit flies. To identify compounds that increase levels of mutant TPI, we have developed a human embryonic kidney (HEK) stable knock-in model expressing the common TPI Df protein fused with green fluorescent protein (HEK TPIE105D-GFP). To directly address the need for lead TPI Df therapeutics, these cells were developed into an optical drug discovery platform that was implemented for high-throughput screening (HTS) and validated in 3-day variability tests, meeting HTS standards. We initially used this assay to screen the 446-member National Institutes of Health (NIH) Clinical Collection and validated two of the hits in dose–response, by limited structure–activity relationship studies with a small number of analogs, and in an orthogonal, non-optical assay in patient fibroblasts. The data form the basis for a large-scale phenotypic screening effort to discover compounds that stabilize TPI as treatments for this devastating childhood disease.


2019 ◽  
Vol 30 (5) ◽  
pp. 554-565 ◽  
Author(s):  
Amy E. Ford ◽  
Catherine Denicourt ◽  
Kevin A. Morano

The eukaryotic cytosolic proteome is vulnerable to changes in proteostatic and redox balance caused by temperature, pH, oxidants, and xenobiotics. Cysteine-containing proteins are especially at risk, as the thiol side chain is subject to oxidation, adduction, and chelation by thiol-reactive compounds. The thiol-chelating heavy metal cadmium is a highly toxic environmental pollutant demonstrated to induce the heat shock response and recruit protein chaperones to sites of presumed protein aggregation in the budding yeast Saccharomyces cerevisiae. However, endogenous targets of cadmium toxicity responsible for these outcomes are largely unknown. Using fluorescent protein fusion to cytosolic proteins with known redox-active cysteines, we identified the yeast glycolytic enzyme triose phosphate isomerase as being aggregation-prone in response to cadmium and to glucose depletion in chronologically aging cultures. Cadmium-induced aggregation was limited to newly synthesized Tpi1 that was recruited to foci containing the disaggregase Hsp104 and the peroxiredoxin chaperone Tsa1. Misfolding of nascent Tpi1 in response to both cadmium and glucose-depletion stress required both cysteines, implying that thiol status in this protein directly influences folding. We also demonstrate that cadmium proteotoxicity is conserved between yeast and human cells, as HEK293 and HCT116 cell lines exhibit recruitment of the protein chaperone Hsp70 to visible foci. Moreover, human TPI, mutations in which cause a glycolytic deficiency syndrome, also forms aggregates in response to cadmium treatment, suggesting that this conserved enzyme is folding-labile and may be a useful endogenous model for investigating thiol-specific proteotoxicity.


2020 ◽  
Vol 2 ◽  
pp. e13
Author(s):  
Neville Y. Forlemu ◽  
Joseph Sloop

Malaria is a disease with debilitating health and negative economic impacts in regions at high risk of infection. Parasitic resistance and side effects of current antimalarial drugs are major setbacks to the successful campaigns that have reduced malaria incidence by 40% in the last decade. The parasite’s dependence on glycolysis for energy requirements makes pathway enzymes suitable targets for drug development. Specifically, triose phosphate isomerase (TPI) from Plasmodium falciparum (pTPI) and human (hTPI) cells show striking structural features that can be used in development of new antimalarial agents. In this study MD simulations were used to characterize binding sites on hTPI and pTPI interactions with sulfonamides. The molecular mechanics Poisson–Boltzmann surface area (MM–PBSA) method was used to estimate the interaction energies of four sulfonamide-TPI docked complexes. A unique combination of key residues at the dimer interface of pTPI is responsible for the observed selective affinity to pTPI compared to hTPI. The representative sulfonamide; 4-amino-N-(3,5-dimethylphenyl)-3-fluorbenzenesulfonamide (sulfaE) shows a strong affinity with pTPI (dimer interface, −42.91 kJ/mol and active site region, −71.62 kJ/mol), hTPI (dimer interface, −41.32 kJ/mol and active site region, −84.40 kJ/mol). Strong and favorable Van der Waals interactions and increases in non-polar solvation energies explain the difference in affinity between pTPI with sulfaE compared to hTPI at the dimer interface. This is an indication that the dimer interface of TPI glycolytic enzyme is vital for development of sulfonamide based antimalarial drugs.


1973 ◽  
Vol 135 (1) ◽  
pp. 165-172 ◽  
Author(s):  
Stephen G. Waley

The refolding and reactivation of the glycolytic enzyme triose phosphate isomerase (EC 5.3.1.1) has been studied. The enzyme, which is a dimer, is disaggregated and unfolded in solutions of guanidinium chloride. Unfolding, followed by changes in E233, took place quite rapidly in 3m-guanidinium chloride (i.e. with a half-life of about 1 min). Refolding also took place rapidly when the solution was diluted about tenfold; two first-order processes could be resolved. Regain of enzymic activity was followed by diluting the solution of the denatured enzyme in guanidinium chloride into assay mixture. The half-life (i.e. the time when the activity was half the final activity) depended markedly on the concentration of protein at low concentrations (about 100ng/ml), but at higher concentrations the half-life became independent of concentration. Thus at low concentrations dimerization was a rate-determining step and this is taken to indicate that the monomers showed little or no activity under these conditions. The rate of regain of enzymic activity was the same as the rate of the slower process of refolding, which was detected spectroscopically. The native enzyme was resistant to proteolysis; high concentrations of subtilisin prevented regain of activity, but at lower concentrations refolding competed with proteolysis.


Author(s):  
Georgi Derluguian

The author develops ideas about the origin of social inequality during the evolution of human societies and reflects on the possibilities of its overcoming. What makes human beings different from other primates is a high level of egalitarianism and altruism, which contributed to more successful adaptability of human collectives at early stages of the development of society. The transition to agriculture, coupled with substantially increasing population density, was marked by the emergence and institutionalisation of social inequality based on the inequality of tangible assets and symbolic wealth. Then, new institutions of warfare came into existence, and they were aimed at conquering and enslaving the neighbours engaged in productive labour. While exercising control over nature, people also established and strengthened their power over other people. Chiefdom as a new type of polity came into being. Elementary forms of power (political, economic and ideological) served as a basis for the formation of early states. The societies in those states were characterised by social inequality and cruelties, including slavery, mass violence and numerous victims. Nowadays, the old elementary forms of power that are inherent in personalistic chiefdom are still functioning along with modern institutions of public and private bureaucracy. This constitutes the key contradiction of our time, which is the juxtaposition of individual despotic power and public infrastructural one. However, society is evolving towards an ever more efficient combination of social initiatives with the sustainability and viability of large-scale organisations.


Genetics ◽  
2001 ◽  
Vol 159 (4) ◽  
pp. 1765-1778
Author(s):  
Gregory J Budziszewski ◽  
Sharon Potter Lewis ◽  
Lyn Wegrich Glover ◽  
Jennifer Reineke ◽  
Gary Jones ◽  
...  

Abstract We have undertaken a large-scale genetic screen to identify genes with a seedling-lethal mutant phenotype. From screening ~38,000 insertional mutant lines, we identified >500 seedling-lethal mutants, completed cosegregation analysis of the insertion and the lethal phenotype for >200 mutants, molecularly characterized 54 mutants, and provided a detailed description for 22 of them. Most of the seedling-lethal mutants seem to affect chloroplast function because they display altered pigmentation and affect genes encoding proteins predicted to have chloroplast localization. Although a high level of functional redundancy in Arabidopsis might be expected because 65% of genes are members of gene families, we found that 41% of the essential genes found in this study are members of Arabidopsis gene families. In addition, we isolated several interesting classes of mutants and genes. We found three mutants in the recently discovered nonmevalonate isoprenoid biosynthetic pathway and mutants disrupting genes similar to Tic40 and tatC, which are likely to be involved in chloroplast protein translocation. Finally, we directly compared T-DNA and Ac/Ds transposon mutagenesis methods in Arabidopsis on a genome scale. In each population, we found only about one-third of the insertion mutations cosegregated with a mutant phenotype.


1979 ◽  
Vol 6 (2) ◽  
pp. 70-72
Author(s):  
T. A. Coffelt ◽  
F. S. Wright ◽  
J. L. Steele

Abstract A new method of harvesting and curing breeder's seed peanuts in Virginia was initiated that would 1) reduce the labor requirements, 2) maintain a high level of germination, 3) maintain varietal purity at 100%, and 4) reduce the risk of frost damage. Three possible harvesting and curing methods were studied. The traditional stack-pole method satisfied the latter 3 objectives, but not the first. The windrow-combine method satisfied the first 2 objectives, but not the last 2. The direct harvesting method satisfied all four objectives. The experimental equipment and curing procedures for direct harvesting had been developed but not tested on a large scale for seed harvesting. This method has been used in Virginia to produce breeder's seed of 3 peanut varieties (Florigiant, VA 72R and VA 61R) during five years. Compared to the stackpole method, labor requirements have been reduced, satisfactory levels of germination and varietal purity have been obtained, and the risk of frost damage has been minimized.


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