Search results for "protein"

A self-inducible heterologous protein expression system in Escherichia coli

2016

AbstractEscherichia coli is an important experimental, medical and industrial cell factory for recombinant protein production. The inducible lac promoter is one of the most commonly used promoters for heterologous protein expression in E. coli. Isopropyl-β-D-thiogalactoside (IPTG) is currently the most efficient molecular inducer for regulating this promoter’s transcriptional activity. However, limitations have been observed in large-scale and microplate production, including toxicity, cost and culture monitoring. Here, we report the novel SILEX (Self-InducibLe Expression) system, which is a convenient, cost-effective alternative that does not require cell density monitoring or IPTG inducti…

Successive Losses of Central Immune Genes Characterize the Gadiformes' Alternate Immunity.

2016

Great genetic variability among teleost immunomes, with gene losses and expansions of central adaptive and innate components, has been discovered through genome sequencing over the last few years. Here, we demonstrate that the innate Myxovirus resistance gene (Mx) is lost from the ancestor of Gadiformes and the closely related Stylephorus chordatus, thus predating the loss of Major Histocompatibility Complex class II (MHCII) in Gadiformes. Although the functional implication of Mx loss is still unknown, we demonstrate that this loss is one of several ancient events appearing in successive order throughout the evolution of teleost immunity. In particular, we find that the loss of Toll-like r…

The aminophosphonate glyphosine enhances phycobiliprotein yields from selected cyanobacterial cultures

2017

Among added-value products obtained from cyanobacterial cultures are phycobiliproteins, photosynthetic pigments that have found an increasing number of applications as natural dyes for food, cosmetics, pharmaceuticals, and antioxidants. To obtain sustainable production, we aimed at maximizing phycobilin yield through the increase of either the final biomass or the specific content of these pigments by varying culture parameters, such as chemical composition and pH of the medium or quality and intensity of the light. Here, we report that the addition to the culture medium of millimolar or submillimolar concentrations of the aminophosphonate glyphosine [(N,N-bis(phosphonomethyl)glycine], form…

Colorado potato beetle chymotrypsin genes are differentially regulated in larval midgut in response to the plant defense inducer hexanoic acid or the…

2019

When Colorado potato beetle larvae ingested potato plants treated with the plant defense inducer compound hexanoic acid, midgut chymotrypsin enzyme activity increased, and the corresponding chymotrypsin genes were differentially expressed, evidence of the larval digestive proteolytic system's plasticity. We previously reported increased susceptibility to Cry3Aa toxin in larvae fed hexanoic acid treated plants. Here we show that the most expressed chymotrypsin gene in larvae fed hexanoic acid treated plants, CTR6, was dramatically downregulated in Cry3Aa intoxicated larvae. lde-miR-965-5p and lde-miR-9a-5p microRNAs, predicted to target CTR6, might be involved in regulating the response to h…

cDNA sequences of two arylphorin subunits of an insect biliprotein: phylogenetic differences and gene duplications during evolution of hexamerins-imp…

2016

Arylphorins represent a conserved class of hexameric ∼500 kDa insect hemolymph glycoproteins, rich in aromatic amino acids, which are produced in large quantities at the larval stage as reserves for metamorphosis and egg development. The recently isolated arylphorin from the moth Cerura vinula is unique in being complexed to a novel farnesylated bilin. Protein sequencing suggested the presence of two different ∼85 kDa subunits. Here, we report the complete coding sequences of two cDNAs encoding two arylphorins subunits with 67% identity and calculated physicochemical characteristics in agreement with the isolated holoprotein. Our phylogenetic analyses of the hexamerins revealed monophyletic…

2017

C4 photosynthesis is a carbon-concentrating mechanism that evolved independently more than 60 times in a wide range of angiosperm lineages. Among other alterations, the evolution of C4 from ancestral C3 photosynthesis requires changes in the expression of a vast number of genes. Differential gene expression analyses between closely related C3 and C4 species have significantly increased our understanding of C4 functioning and evolution. In Chenopodiaceae, a family that is rich in C4 origins and photosynthetic types, the anatomy, physiology and phylogeny of C4, C2, and C3 species of Salsoleae has been studied in great detail, which facilitated the choice of six samples of five representative …

Acceptor Specificity of Amylosucrase from Deinococcus radiopugnans and Its Application for Synthesis of Rutin Derivatives

2016

The transglycosylation activity of amylosucrase (ASase) has received significant attention owing to its use of an inexpensive donor, sucrose, and broad acceptor specificity, including glycone and aglycone compounds. The transglycosylation reaction of recombinant ASase from Deinococcus radiopugnans (DRpAS) was investigated using various phenolic compounds, and quercetin-3-O-rutinoside (rutin) was found to be the most suitable acceptor molecule used by DRpAS. Two amino acid residues in DRpAS variants (DRpAS Q299K and DRpAS Q299R), assumed to be involved in acceptor binding, were constructed by site-directed mutagenesis. Intriguingly, DRpAS Q299K and DRpAS Q299R produced 10-fold and 4-fold hig…

GIPC: Glycosyl Inositol Phospho Ceramides, the major sphingolipids on earth

2016

What are the most abundant sphingolipids on earth? The answer is Glycosyl Inositol Phosphoryl Ceramides (GIPCs) present in fungi and the green lineage. In this review, we discuss the putative role of plant GIPCs in the lipid bilayer asymmetry, in the lateral organization of membrane rafts and in the very long chain fatty acid inter-leaflet coupling of lipids in the plant plasma membrane (PM). A special focus on the structural similarities -and putative functions- of GIPCs is discussed by comparison with animal gangliosides, structural homologs of plant GIPCs.

Isolating, characterising and identifying a Cry1Ac resistance mutation in field populations of Helicoverpa punctigera

2018

AbstractTransgenic cotton expressing insecticidal proteins from Bacillus thuringiensis (Bt) has been grown in Australia for over 20 years and resistance remains the biggest threat. The native moth, Helicoverpa punctigera is a significant pest of cotton. A genotype causing resistance to Cry1Ac in H. punctigera was isolated from the field and a homozygous line established. The phenotype is recessive and homozygous individuals possess 113 fold resistance to Cry1Ac. Individuals that carry Cry1Ac resistance genes are rare in Australia with a frequency of 0.033 being detected in field populations. RNAseq, RT-PCR and DNA sequencing reveals a single nucleotide polymorphism at a splice site in the c…

The chaperone-like protein Cdc48 regulates ubiquitin-proteasome system in plants.

2021

The degradation of misfolded proteins is mainly mediated by the ubiquitin-proteasome system (UPS). UPS can be assisted by the protein Cdc48 but the relationship between UPS and Cdc48 in plants has been poorly investigated. Here, we analyzed the regulation of UPS by Cdc48 in tobacco thanks to two independent cell lines overexpressing Cdc48 constitutively and plant leaves overexpressing Cdc48 transiently. In the cell lines, the accumulation of ubiquitinated proteins was affected both quantitatively and qualitatively and the amount of proteasomal subunits was modified, while proteolytic activities were unchanged. Similarly, the over-expression of Cdc48 in planta impacted the accumulation of ub…