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Autophagy initiation triggers p150Glued–AP-2β interaction on the lysosomes and facilitates their transport
Get PDFAn Evaluation of Long‑Term Contaminated Soil from a Manufactured Gas Plant for in Situ Biodegradation Potential and as a Source of Ferrocyanide‑Degrading Bacteria
Get PDFDespite the high abundance and potential toxicity of ferrocyanide in the environment, data on the bioremediation of these complexes in contaminated soils are missing. In this study we isolated forty bacterial species presented in soil highly contaminated with ferrocyanide complexes, originating from a Manufactured Gas Plant (MGP). All bacterial strains were resistant to ferrocyanide (500 mg L−1). Six isolates showed better growth in the presence of ferrocyanide and were able to use it as a sole nitrogen source. One of them was able to assimilate ferrocyanide‐derived nitrogen and carbon. The strains varied in their tolerance to the ferrocyanide. The Minimum Inhibitory Concentration (MIC) values determined in the rich medium ranged from 1400 mg L−1 to 2000 mg L−1 and in all cases were greater than those set on the minimal medium. Molecular analysis revealed that the investigated isolates had the highest similarity to the Bacillus and Rummeliibacillus lineages. Rummeliibacillus was recognized for the first time for its ferrocyanide-degrading potential. Soil samples collected from MGP sites indicated that the overall indigenous population of microorganisms was low. Total cyanide content ranged from 220 mg kg−1 to 346 mg kg−1. Additionally, elevated Pb concentrations and an imbalanced C:N:P ratio were observed. Our study provides new information about the presence of a well-acclimated bacterial community associated with long-term ferrocyanide-contaminated soil. This bacterial community could play an important role in MGP site bioremediation processes and has the potential for application for other bioremediation purposes; however, it is likely limited due to unfavorable environmental conditions
Light-independent pathway of STN7 kinase activation under low temperature stress in runner bean (Phaseolus coccineus L.)
Get PDFBackground
The phosphorylation of the Light-Harvesting Complex of photosystem II (LHCII) driven by STATE TRANSITION 7 (STN7) kinase is a part of one of the crucial regulatory mechanisms of photosynthetic light reactions operating in fluctuating environmental conditions, light in particular. There are evidenced that STN7 can also be activated without light as well as in dark-chilling conditions. However, the biochemical mechanism standing behind this complex metabolic pathway has not been deciphered yet.
Results
In this work, we showed that dark-chilling induces light-independent LHCII phosphorylation in runner bean (Phaseolus coccineus L.). In dark-chilling conditions, we registered an increased reduction of the PQ pool which led to activation of STN7 kinase, subsequent LHCII phosphorylation, and possible LHCII relocation inside the thylakoid membrane. We also presented the formation of a complex composed of phosphorylated LHCII and photosystem I typically formed upon light-induced phosphorylation. Moreover, we indicated that the observed steps were preceded by the activation of the oxidative pentose phosphate pathway (OPPP) enzymes and starch accumulation.
Conclusions
Our results suggest a direct connection between photosynthetic complexes reorganization and dark-chilling-induced activation of the thioredoxin system. The proposed possible pathway starts from the activation of OPPP enzymes and further NADPH-dependent thioredoxin reductase C (NTRC) activation. In the next steps, NTRC simultaneously activates ADP-glucose pyrophosphorylase and thylakoid membrane-located NAD(P)H dehydrogenase-like complex. These results in starch synthesis and electron transfer to the plastoquinone (PQ) pool, respectively. Reduced PQ pool activates STN7 kinase which phosphorylates LHCII. In this work, we present a new perspective on the mechanisms involving photosynthetic complexes while efficiently operating in the darkness. Although we describe the studied pathway in detail, taking into account also the time course of the following steps, the biological significance of this phenomenon remains puzzling
The PIWI-interacting protein Gtsf1 controls the selective degradation of small RNAs in Paramecium
Get PDFCiliates undergo developmentally programmed genome elimination, in which small RNAs direct the removal of transposable elements during the development of the somatic nucleus. 25-nt scnRNAs are produced from the entire germline genome and transported to the maternal somatic nucleus, where selection of scnRNAs corresponding to germline-specific sequences is thought to take place. Selected scnRNAs then guide the elimination of transposable elements in the developing somatic nucleus. How germline-specific scnRNAs are selected remains to be determined. Here, we provide important mechanistic insights into the scnRNA selection pathway by identifying a Paramecium homolog of Gtsf1 as essential for the selective degradation of scnRNAs corresponding to retained somatic sequences. Consistently, we also show that Gtsf1 is localized in the maternal somatic nucleus where it associates with the scnRNA-binding protein Ptiwi09. Furthermore, we demonstrate that the scnRNA selection process is critical for genome elimination. We propose that Gtsf1 is required for the coordinated degradation of Ptiwi09-scnRNA complexes that pair with target RNA via the ubiquitin pathway, similarly to the mechanism suggested for microRNA target-directed degradation in metazoans
Recurrent Supramolecular Patterns in a Series of Salts of Heterocyclic Polyamines and Heterocyclic Dicarboxylic Acids: Synthesis, Single-Crystal X-ray Structure, Hirshfeld Surface Analysis, Energy Framework, and Quantum Chemical Calculations
Get PDFA series of novel salts based on aromatic polyamines and 2,3-pyrazinedicarboxylic acid, such as C10H12N6O5 (1), C10H9ClN6O4 (2), C11H10N8O4 (3), and C14H17N16O5.5 (4) or 3,4-thiophenedicarboxylic acid, such as C10H10N4O4S (5), C10H9ClN4O4S (6), and C10H10N4O4S2 (7), were synthesized and characterized by single-crystal X-ray diffraction. All compounds crystallize in a monoclinic space group. The structure was subjected to complex Hirshfeld surface analysis, molecular electrostatic potential, enrichment ratio, and energy framework calculations. The influence of different cations on the packing of 3-carboxypyrazine-2-carboxylate and 4-carboxythiophene-3-carboxylate anions in the crystal lattice was studied. O…H/H…O interactions are the main contributor in all crystals. In addition, in a series of pyrazine-containing structures, N(C)…H/H…N(C) interactions have relevance, while in a series of thiophene-based compounds, C…H/H…C and S…H(O)/H(O)…S. In addition, Cl-based interactions are observed in compound 2. According to the enrichment ratio calculations, O…H/H…O and C…C are the most preferable interactions in all structures. The energy frameworks are dominated by the dispersive contribution, only in compound 3 is the electrostatic term dominant. The analyzed structures reveal intra- and intermolecular recurrent supramolecular synthons. In both series of crystals, the robust H-bonded centrosymmetric dimer R22(8) as homo- or as heterosynthon (in compounds 2, 3, 6, and 7) and the intramolecular synthon S(7) generated by O-H…O interactions (in compounds 2, 6, and 7) are present. The supramolecular patterns formed by π…π (C…C) and C-O(Cl,S)…C are also noticeable. Notably, a dual synthon linking the supramolecular chain via π…π interactions and the homosynthon R22(8) via N-H…N interactions is visible in both series of new salts. A library of H-bonding motifs at diverse levels of supramolecular architecture is provided. We extended the analysis of intramolecular H-bonding motifs to similar structures deposited in the Cambridge Structural Database. Another important feature is the existence of an intramolecular O…H…O bridge between two neighboring carboxylic groups as substituents in anions in compounds 3 and 5. In this context, we performed quantum theory of atoms-in-molecule calculations to reveal more details
Bayesian reweighting of biomolecular structural ensembles using heterogeneous cryo-EM maps with the cryoENsemble method.
Get PDFCryogenic electron microscopy (cryo-EM) has emerged as a powerful method for the determination of structures of complex biological molecules. The accurate characterisation of the dynamics of such systems, however, remains a challenge. To address this problem, we introduce cryoENsemble, a method that applies Bayesian reweighting to conformational ensembles derived from molecular dynamics simulations to improve their agreement with cryo-EM data, thus enabling the extraction of dynamics information. We illustrate the use of cryoENsemble to determine the dynamics of the ribosome-bound state of the co-translational chaperone trigger factor (TF). We also show that cryoENsemble can assist with the interpretation of low-resolution, noisy or unaccounted regions of cryo-EM maps. Notably, we are able to link an unaccounted part of the cryo-EM map to the presence of another protein (methionine aminopeptidase, or MetAP), rather than to the dynamics of TF, and model its TF-bound state. Based on these results, we anticipate that cryoENsemble will find use for challenging heterogeneous cryo-EM maps for biomolecular systems encompassing dynamic components
Recombinant C-Terminal Catalytic Domain of Rat L-Gulono Lactone Oxidase Produced in Bacterial Cells Is Enzymatically Active
Get PDFThe L-gulonolactone oxidase enzyme (GULO) catalyzes the last step of L-ascorbic acid (vitamin C) biosynthesis. This enzymatic activity is lost in primates. The full-length rat GULO has been previously produced in plants and demonstrated to be active. In this study, we compared the activity of two variants of GULO produced in Escheriachia coli cells, full-length rat GULO (fGULO) and its C-terminal catalytic domain (cGULO). The expression and purification of the recombinant proteins were optimized, and their biological activity was confirmed by two methods, the GULO activity assay in the protein extracts and the ‘in-gel’ staining for GULO activity. Both variants of recombinant GULO were biologically active in both assays. However, cGULO is more promising than fGULO for ascorbic acid production because it is more efficiently produced by bacteria. Furthermore, the optimal activities of the fGULO and cGULO recombinant proteins were observed at pH 7 and 6.5, and at temperatures of 40 and 30 °C, respectively. Kinetic studies revealed that at low substrate concentrations, Km values for fGULO and cGULO were 53.5 ± 5 and 42 ± 6.3 µM, respectively
Phototropin2 3’UTR overlaps with the AT5G58150 gene encoding an inactive RLK kinase
Get PDFackground This study examines the biological implications of an overlap between two sequences in the Arabidop�sis genome, the 3’UTR of the PHOT2 gene and a putative AT5G58150 gene, encoded on the complementary strand.
AT5G58150 is a probably inactive protein kinase that belongs to the transmembrane, leucine-rich repeat receptor-like
kinase family. Phot2 is a membrane-bound UV/blue light photoreceptor kinase. Thus, both proteins share their cellular
localization, on top of the proximity of their loci.
Results The extent of the overlap between 3’UTR regions of AT5G58150 and PHOT2 was found to be 66 bp, using
RACE PCR. Both the at5g58150 T-DNA SALK_093781C (with insertion in the promoter region) and 35S::AT5G58150�GFP lines overexpress the AT5G58150 gene. A detailed analysis did not reveal any substantial impact of PHOT2
or AT5G58150 on their mutual expression levels in diferent light and osmotic stress conditions. AT5G58150 is a plasma
membrane protein, with no apparent kinase activity, as tested on several potential substrates. It appears not to form
homodimers and it does not interact with PHOT2. Lines that overexpress AT5G58150 exhibit a greater reduction in lat‑
eral root density due to salt and osmotic stress than wild-type plants, which suggests that AT5G58150 may partici‑
pate in root elongation and formation of lateral roots. In line with this, mass spectrometry analysis identifed proteins
with ATPase activity, which are involved in proton transport and cell elongation, as putative interactors of AT5G58150.
Membrane kinases, including other members of the LRR RLK family and BSK kinases (positive regulators of brassinos‑
teroid signalling), can also act as partners for AT5G58150.
Conclusions AT5G58150 is a membrane protein that does not exhibit measurable kinase activity, but is involved
in signalling through interactions with other proteins. Based on the interactome and root architecture analysis,
AT5G58150 may be involved in plant response to salt and osmotic stress and the formation of roots in Arabidopsis
Reducing Immunoreactivity of Gluten Peptides by Probiotic Lactic Acid Bacteria for Dietary Management of Gluten-Related Diseases
Get PDFImmunoreactive gluten peptides that are not digested by peptidases produced by humans
can trigger celiac disease, allergy and non-celiac gluten hypersensitivity. The aim of this study was
to evaluate the ability of selected probiotic strains to hydrolyze immunoreactive gliadin peptides
and to identify peptidase-encoding genes in the genomes of the most efficient strains. Residual
gliadin immunoreactivity was measured after one- or two-step hydrolysis using commercial
enzymes and bacterial peptidase preparations by G12 and R5 immunoenzymatic assays. Peptidase
preparations from Lacticaseibacillus casei LC130, Lacticaseibacillus paracasei LPC100 and Streptococcus
thermophilus ST250 strains significantly reduced the immunoreactivity of gliadin peptides, including
33-mer, and this effect was markedly higher when a mixture of these strains was used. In silico
genome analyses of L. casei LC130 and L. paracasei LPC100 revealed the presence of genes encoding
peptidases with the potential to hydrolyze bonds in proline-rich peptides. This suggests that L. casei
LC130, L. paracasei LPC100 and S. thermophilus ST250, especially when used as a mixture, have the
ability to hydrolyze immunoreactive gliadin peptides and could be administered to patients on a
restricted gluten-free diet to help treat gluten-related diseases
Novel Salts of Heterocyclic Polyamines and 5-Sulfosalicylic Acid: Synthesis, Crystal Structure, and Hierarchical Supramolecular Interactions
Get PDFA series of novel salts of heterocyclic polyamines with 5-sulfosalicylic acid (C4H7N4+)(C7H5O6S−)∙2(H2O) (1), (C4H6ClN4+)(C7H5O6S−)∙H2O (2), (C5H8N3+)(C7H5O6S−)∙H2O (3), (C5H7N6+)(C7H5O6S−)∙H2O (4), (C6H14N22+)(C7H4O6S2−)∙H2O (5), and (C14H19N2+)(C7H5O6S−) (6) have been successfully synthesized. Their crystal structures have been determined by single-crystal X-ray diffraction. Overall, compounds adopt a layered structure with aminium cations and 5-sulfosalicylic anions linked via water molecules. The solid-state architectures of these compounds are dominated by O(N,H)-H⋯O and N-H⋯N hydrogen bonds and stabilized by weak interconnects. C-Cl⋯π and S-O⋯π interactions, apart from π⋯π and C-H(O)⋯π, were reported. Diverse approaches were used to study the effect of substituents in the polyamines in solid-state arrangement. A Hirshfeld surface analysis, with associated 3D Hirshfeld surface maps and 2D fingerprint plots, molecular electrostatic potential, and energy frameworks were used to comprehensively investigate the nature and hierarchy of non-covalent interactions and inspect supramolecular differences. The contact enrichment ratio calculations provided deeper insight into the propensity of interconnects to influence crystal packing. The evaluation of the effects of H-bonding synthons resulting from different substituents in the polyamines on self-assemblies is also presented. In the context of crystal engineering, a specific intramolecular synthon via O-H⋯O observed in nearly all crystals can be employed in the pseudo-cyclic replacement strategy in the design of new molecules