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Plant Molecular Biology Nov 2022We propose that anion channels are essential players for green plants to respond and adapt to the abiotic stresses associated changing climate via reviewing the... (Review)
Review
We propose that anion channels are essential players for green plants to respond and adapt to the abiotic stresses associated changing climate via reviewing the literature and analyzing the molecular evolution, comparative genetic analysis, and bioinformatics analysis of the key anion channel gene families. Climate change-induced abiotic stresses including heatwave, elevated CO, drought, and flooding, had a major impact on plant growth in the last few decades. This scenario could lead to the exposure of plants to various stresses. Anion channels are confirmed as the key factors in plant stress responses, which exist in the green lineage plants. Numerous studies on anion channels have shed light on their protein structure, ion selectivity and permeability, gating characteristics, and regulatory mechanisms, but a great quantity of questions remain poorly understand. Here, we review function of plant anion channels in cell signaling to improve plant response to environmental stresses, focusing on climate change related abiotic stresses. We investigate the molecular response and evolution of plant slow anion channel, aluminum-activated malate transporter, chloride channel, voltage-dependent anion channel, and mechanosensitive-like anion channel in green plant. Furthermore, comparative genetic and bioinformatic analysis reveal the conservation of these anion channel gene families. We also discuss the tissue and stress specific expression, molecular regulation, and signaling transduction of those anion channels. We propose that anion channels are essential players for green plants to adapt in a diverse environment, calling for more fundamental and practical studies on those anion channels towards sustainable food production and ecosystem health in the future.
Topics: Ecosystem; Ion Transport; Stress, Physiological; Plants; Anions
PubMed: 34846607
DOI: 10.1007/s11103-021-01216-x -
Chemistry (Weinheim An Der Bergstrasse,... Jan 2022Since its discovery two decades ago, anion-π interaction has been increasingly recognized as an important driving force. Extensive theoretical and experimental efforts...
Since its discovery two decades ago, anion-π interaction has been increasingly recognized as an important driving force. Extensive theoretical and experimental efforts on the ground-state anion-π binding and recognition have laid the bases for exploring its relevance in catalysis. Accordingly, the concept of "anion-π catalysis" that employing an electron-deficient π surface (π-acidic surface) for anionic reaction intermediate and transition state stabilization has emerged. This article shortly reviews the emergence and development of this concept, aiming to provide an emphasis on the general concept and key progress in this exciting area. To highlight the essential contribution of anion-π interactions, the contents are organized according to their role engaged in catalytic process, for example from both ground-state and transition-state stabilization to solely transition-state stabilization, mainly by a single π-face, and to cooperative π-face activation. A concluding remark and outlook on future development of this field is also given.
Topics: Anions; Catalysis; Electrons; Models, Molecular
PubMed: 34658085
DOI: 10.1002/chem.202103303 -
Analytical Biochemistry May 2022In the 1960s, my lab was interested in understanding how bilirubin and other organic anions are transferred from the plasma through the liver cell and into the bile. We...
In the 1960s, my lab was interested in understanding how bilirubin and other organic anions are transferred from the plasma through the liver cell and into the bile. We performed gel filtration of liver supernatants and identified two protein fractions, designated Y and Z, which bound organic anions including bilirubin, and thus we proposed that they were involved in hepatic uptake of organic anions from plasma. Subsequently, the Y and Z proteins responsible for this binding activity were purified, cloned, and sequenced. With Bill Jakoby, we identified Y protein as a member of the glutathione S-transferase (GST) protein family. In separate studies, Z was found to be a member of the fatty acid-binding protein (FABP) family. These proteins have since been shown to have additional surprising roles, but understanding of their full role in physiology and disease has not yet been achieved. In the 1960s, bilirubin metabolism was a "hot" topic. Along with other groups, my lab was studying various forms of inheritable jaundice in an effort to dissect the mechanism of bilirubin's transfer from plasma into the hepatocyte and its role in intracellular metabolism and biliary secretion. These processes were eventually identified and found to be related to the basic mechanisms whereby the liver handles many anionic drugs, metabolites, and hormones. Because the mechanism of hepatic uptake of bilirubin was unknown, A.J. Levi, Z. Gatmaitan, and I took advantage of advances in gel permeation chromatography to study this process. In 1969, we described two hepatic cytoplasmic protein fractions, designated Y and Z, that bound bilirubin and various organic anionic dyes in vivo and in vitro and, based on tissue distribution, abundance, and effects of genetic and pharmacologic models, were proposed to participate in organic anion uptake (Levi et al., 1969) [1]. In the decades since then, the Y and Z proteins have been identified as members of large protein families that were cloned and sequenced. Several surprising functions emerged, whereas others are proposed based on binding properties. Many challenges remain in understanding the full role of these proteins in physiology and disease.
Topics: Anions; Bilirubin; Glutathione Transferase; Liver; Proteins; Sulfobromophthalein
PubMed: 34653415
DOI: 10.1016/j.ab.2021.114414 -
Inorganic Chemistry Jun 2022The previously unexplored noncovalent binding of the highly toxic tetrafluoroberyllate anion (BeF) and its extraction from water into organic solvents are presented....
The previously unexplored noncovalent binding of the highly toxic tetrafluoroberyllate anion (BeF) and its extraction from water into organic solvents are presented. Nanojars resemble anion-binding proteins in that they also possess an inner anion binding pocket lined by a multitude of H-bond donors (OH groups), which wrap around the incarcerated anion and completely isolate it from the surrounding medium. The BeF-binding propensity of [BeF⊂{Cu(OH)(pz)}] (pz = pyrazolate; = 27-32) nanojars of different sizes is investigated using an array of techniques including mass spectrometry, paramagnetic H, Be, and F NMR spectroscopy, and X-ray crystallography, along with thermal stability studies in solution and chemical stability studies toward acidity and Ba ions. The latter is found to be unable to precipitate the insoluble BaBeF from nanojar solutions, indicating a very strong binding of the BeF anion by nanojars. Be and F NMR spectroscopy allows for the unprecedented direct probing of the incarcerated anion in a nanojar and, along with H NMR studies, reveals the fluxional structure of nanojars and their inner anion-binding pockets. Single-crystal X-ray diffraction provides the crystal and molecular structures of (BuN)[BeF⊂{Cu(OH)(pz)}], which contains a novel Cu-ring combination ( = 9 + 14 + 9), (BuN)[BeF⊂{Cu(OH)(pz)}], and (BuN)[BeF⊂{Cu(OH)(pz)}] and offers detailed structural parameters related to the supramolecular binding of BeF in these nanojars. The extraction of BeF from water into organic solvents, including the highly hydrophobic solvent -heptane, demonstrates that nanojars are efficient binding and extracting agents not only for oxoanions but also for fluoroanions.
Topics: Anions; Crystallography, X-Ray; Models, Molecular; Solvents; Water
PubMed: 35617675
DOI: 10.1021/acs.inorgchem.2c01198 -
International Journal of Molecular... May 2023Redox properties of monoiminoacenaphthenes (MIANs) were studied using various electrochemical techniques. The potential values obtained were used for calculating the...
Redox properties of monoiminoacenaphthenes (MIANs) were studied using various electrochemical techniques. The potential values obtained were used for calculating the electrochemical gap value and corresponding frontier orbital difference energy. The first-peak-potential reduction of the MIANs was performed. As a result of controlled potential electrolysis, two-electron one-proton addition products were obtained. Additionally, the MIANs were exposed to one-electron chemical reduction by sodium and NaBH. Structures of three new sodium complexes, three products of electrochemical reduction, and one product of the reduction by NaBH were studied using single-crystal X-ray diffraction. The MIANs reduced electrochemically by NaBH represent salts, in which the protonated MIAN skeleton acts as an anion and BuN or Na as a cation. In the case of sodium complexes, the anion radicals of MIANs are coordinated with sodium cations into tetranuclear complexes. The photophysical and electrochemical properties of all reduced MIAN products, as well as neutral forms, were studied both experimentally and quantum-chemically.
Topics: Oxidation-Reduction; Anions; Cations; Sodium
PubMed: 37240012
DOI: 10.3390/ijms24108667 -
Nature Structural & Molecular Biology Nov 2023In mammals, the kidney plays an essential role in maintaining blood homeostasis through the selective uptake, retention or elimination of toxins, drugs and metabolites....
In mammals, the kidney plays an essential role in maintaining blood homeostasis through the selective uptake, retention or elimination of toxins, drugs and metabolites. Organic anion transporters (OATs) are responsible for the recognition of metabolites and toxins in the nephron and their eventual urinary excretion. Inhibition of OATs is used therapeutically to improve drug efficacy and reduce nephrotoxicity. The founding member of the renal organic anion transporter family, OAT1 (also known as SLC22A6), uses the export of α-ketoglutarate (α-KG), a key intermediate in the Krebs cycle, to drive selective transport and is allosterically regulated by intracellular chloride. However, the mechanisms linking metabolite cycling, drug transport and intracellular chloride remain obscure. Here, we present cryogenic-electron microscopy structures of OAT1 bound to α-KG, the antiviral tenofovir and clinical inhibitor probenecid, used in the treatment of Gout. Complementary in vivo cellular assays explain the molecular basis for α-KG driven drug elimination and the allosteric regulation of organic anion transport in the kidney by chloride.
Topics: Animals; Organic Anion Transport Protein 1; Chlorides; Kidney; Biological Transport; Anions; Ketoglutaric Acids; Mammals
PubMed: 37482561
DOI: 10.1038/s41594-023-01039-y -
Dalton Transactions (Cambridge, England... Aug 2022In this work, four new ruthenium complexes [Ru(η--cymene)(L1)Cl] 1, [Ru(η--cymene)(L2)Cl] 2, [Ru(η--cymene)(L3)Cl] 3 and [Ru(η--cymene)(L4)Cl] 4 [HL1 =...
In this work, four new ruthenium complexes [Ru(η--cymene)(L1)Cl] 1, [Ru(η--cymene)(L2)Cl] 2, [Ru(η--cymene)(L3)Cl] 3 and [Ru(η--cymene)(L4)Cl] 4 [HL1 = (2-cyanophenyl)glycine; HL2 = (5-chloro-2-cyanophenyl)glycine; HL3 = (2-cyano-3-fluorophenyl)glycine; HL4 = (4-cyanophenyl)glycine] were synthesized and well characterized by several spectroscopic and analytical techniques. Complexes 1 and 3 were found to be fluorescent in most of the solvents; however, 2 and 4 were found to be fluorescent mostly in EtOAc, DMF and ethanol. Amongst these four complexes, 3 has shown selective sensing against CO and SO anions by quenching of fluorescence. The LOD values are found to be in the sub-micromolar range. Investigations of the sensing mechanism performed by computation and NMR studies indicate a possible adduct formation between the NH group of the ligand and the anion(s) through hydrogen bond formation, which ultimately might lead to proton transfer to the bi-negative anion. The quantum yield of the complex 3 was found to decrease on addition of CO and SO anions from 0.46 to 0.13 and 0.12, respectively. The Job's plot indicates the binding between the probe and anion in a 1 : 1 ratio for both CO and SO anions. Along with that, all the complexes were found to be biocompatible when tested against several cell lines showing very high IC values. It can also be observed that 1 is capable of penetrating within the cells and can act as a cell imaging agent showing fluorescence, and thus can be used for bio-imaging purposes.
Topics: Anions; Antineoplastic Agents; Cell Line, Tumor; Coordination Complexes; Glycine; Ligands; Magnetic Resonance Spectroscopy; Ruthenium
PubMed: 35972307
DOI: 10.1039/d2dt01726a -
Biochemical Society Transactions Dec 2022Chloride is the most abundant inorganic anions in almost all cells and in human circulation systems. Its homeostasis is therefore important for systems physiology and...
Chloride is the most abundant inorganic anions in almost all cells and in human circulation systems. Its homeostasis is therefore important for systems physiology and normal cellular activities. This topic has been extensively studied with chloride loaders and extruders expressed in both cell surfaces and intracellular membranes. With the newly discovered, large-conductance, highly selective Cl- channel formed by membrane-bound chromogranin B (CHGB), which differs from all other known anion channels of conventional transmembrane topology, and is distributed in plasma membranes, endomembrane systems, endosomal, and endolysosomal compartments in cells expressing it, we will discuss the potential physiological importance of the CHGB channels to Cl- homeostasis, cellular excitability and volume control, and cation uptake or release at the cellular and subcellular levels. These considerations and CHGB's association with human diseases make the CHGB channel a possible druggable target for future molecular therapeutics.
Topics: Humans; Chlorides; Chloride Channels; Chromogranin B; Anions; Homeostasis
PubMed: 36511243
DOI: 10.1042/BST20220435 -
Journal of Colloid and Interface Science Jun 2022Despite the much progress in developing π-conjugated fluoroarene moieties based functional materials in which anion - π interactions are commonly involved, it...
Despite the much progress in developing π-conjugated fluoroarene moieties based functional materials in which anion - π interactions are commonly involved, it remains challenging to quantitatively characterize the nanomechanical interaction mechanism of these anion - π systems, particularly in aqueous solutions. In this study, we reported the first experimental quantification of the nanomechanics of anion - π interactions between π-conjugated fluoroarene moieties and carboxylate anions in aqueous solutions through direct molecular force measurements, with a special focus on the impact of the anion species, concentration and of the substitution effect of aromatic side group. The results using surface forces apparatus (SFA) and single-molecule force spectroscopy (SMFS) provide complementary evidences to demonstrate that the robust and reversible adhesion measured between the fluoroarene π systems and carboxylate anions was mainly attributed to anion - π interaction. Moreover, their nanomechanical properties were also systematically scrutinized, with the interaction strength being found to be significantly determined by the contact time, the type of fluoroarene systems (PFST > DFST) and the type of anions and ion concentration (HPO > CO > I > Cl ≈ NO > F).
Topics: Anions; Molecular Dynamics Simulation; Physical Phenomena; Water
PubMed: 35176544
DOI: 10.1016/j.jcis.2022.01.184 -
Organic & Biomolecular Chemistry Nov 2022The anion recognition ability of 2,4,6-triisopropylphenylsilanetriol 5 has been evaluated by H NMR titrations in MeCN-. The anion recognition ability of silanetriol 5...
The anion recognition ability of 2,4,6-triisopropylphenylsilanetriol 5 has been evaluated by H NMR titrations in MeCN-. The anion recognition ability of silanetriol 5 was greater than those of the structurally related silanediols and silanemono-ol, although less effective than those of 1,3-disiloxane-1,3-diol and 1,3-disiloxane-1,1,3,3-tetraol. From the comparison of the association constants and DFT calculations, all three silanol groups of 5 cooperatively hydrogen bonded to anionic species. The catalytic ability of silanetriol 5 for the addition of indole to β-nitrostyrene in CHCl has also been evaluated. Silanetriol 5 acts as a more effective organocatalyst than the corresponding silanediol in this reaction.
Topics: Anions; Acetonitriles
PubMed: 36321688
DOI: 10.1039/d2ob01596j