scholarly journals Metabolic Energy Sensing by Mammalian CLC Anion/Proton Exchangers

2019 ◽  
Author(s):  
Matthias Grieschat ◽  
Katharina Langschwager ◽  
Raul E. Guzman ◽  
Christoph Fahlke ◽  
Alexi K. Alekov
Keyword(s):  
Heterologous Expression ◽  
Protein C ◽  
Voltage Dependence ◽  
Adenine Nucleotide ◽  
Metabolic Energy ◽  
System Components ◽  
Nucleotide Regulation ◽  
Vesicular Transporters ◽  
Energy Sensing ◽  
Cbs Domains

AbstractMammalian CLC anion/proton exchangers control the pH and [Cl-] of the endolysosomal system, one of the major cellular nutrient uptake pathways. We explored the regulation of the vesicular transporters ClC-3, ClC-4, and ClC-5 by the adenylic system components ATP, ADP, and AMP. Using heterologous expression and whole-cell electrophysiology, we demonstrated that cytosolic ATP and ADP but not AMP and Mg2+-free ADP enhance CLC ion transport via binding to the protein C-terminal CBS domains. Biophysical investigations revealed that the effects depend on the delivery of intracellular protons into the CLC transport machinery and result from modified voltage-dependence and altered probability that CLC proteins undergo silent non-transporting cycles. Our findings demonstrate that the CLC CBS domains are able to serve as energy sensors by detecting changes in the cytosolic ATP/ADP/AMP equilibrium. The adenine nucleotide regulation of vesicular Cl-/H+ exchange creates a link between the activity of the endolysosomal system and the cellular metabolic state.

POTENTIAL PRODUCTIVITY ADAPTIVE AGROPHUTOCENOZIS ON SLOPING LANDS OF THE STEPPE TRANS-URALS

2020 ◽  
Author(s):  
R.А. Idrisov ◽  
Keyword(s):  
Protein C ◽  
Nutritional Value ◽  
Energy Content ◽  
Single Species ◽  
Exchange Energy ◽  
Metabolic Energy ◽  
Potential Productivity ◽  
Maximum Productivity ◽  
Sloping Lands ◽  
Natural Herb

The correct construction of agrophytocenoses on the slopes of the steppe trans-Urals helped to create maximum productivity. In the arid climate, the most productive were the double mixtures of alfalfa with brittle sitnik, wheatgrass is syd, providing an average of 41.6 and 40.2 quintals per hectare (c/ha) of hay, 32.1 and 31.0 GJ/ha OE (exchange energy per hectare), 4.5 and 4.3 quintals per hectare of boiled protein (c/ha) over 5 years. Single-species steppe ecotypes, brittle sieve and wheatgrass sieve in productivity slightly gave way to double components, providing respectively hay- 32.2 and 37.2 cents per hectare, exchange energy 22.2 and 25.7 GJ/ha, digested protein 1.93 and 2.53 c/ha. The enrichment of agrophytocense by the legume component allowed to increase the metabolic energy content to the level of 32.1 and 31.0-GJ/ha, digested protein to 4.5 and 4.3 quintals per hectare, which is 14 times the nutritional value of the metabolic energy, the digested protein is 10 times higher than the natural herb.

scholarly journals Metabolic energy sensing by mammalian CLC anion/proton exchangers

EMBO Reports ◽  
2020 ◽  
Vol 21 (6) ◽  
Author(s):  
Matthias Grieschat ◽  
Raul E Guzman ◽  
Katharina Langschwager ◽  
Christoph Fahlke ◽  
Alexi K Alekov
Keyword(s):  
Metabolic Energy ◽  
Energy Sensing

An asparagine residue mediates intramolecular communication in nucleotide-regulated pyrophosphatase

2016 ◽  
Vol 473 (14) ◽  
pp. 2097-2107 ◽  
Author(s):  
Viktor A. Anashkin ◽  
Anu Salminen ◽  
Natalia N. Vorobjeva ◽  
Reijo Lahti ◽  
Alexander A. Baykov
Keyword(s):  
Adenine Nucleotide ◽  
Nucleotide Binding ◽  
Regulatory Domains ◽  
Hydrogen Bonding Pattern ◽  
Cbs Domain ◽  
Subunit Interface ◽  
Desulfitobacterium Hafniense ◽  
Dynamics Simulations ◽  
Cbs Domains ◽  
Asparagine Residue

Many prokaryotic soluble PPases (pyrophosphatases) contain a pair of regulatory adenine nucleotide-binding CBS (cystathionine β-synthase) domains that act as ‘internal inhibitors’ whose effect is modulated by nucleotide binding. Although such regulatory domains are found in important enzymes and transporters, the underlying regulatory mechanism has only begun to come into focus. We reported previously that CBS domains bind nucleotides co-operatively and induce positive kinetic co-operativity (non-Michaelian behaviour) in CBS-PPases (CBS domain-containing PPases). In the present study, we demonstrate that a homodimeric ehPPase (Ethanoligenens harbinense PPase) containing an inherent mutation in an otherwise conserved asparagine residue in a loop near the active site exhibits non-co-operative hydrolysis kinetics. A similar N312S substitution in ‘co-operative’ dhPPase (Desulfitobacterium hafniense PPase) abolished kinetic co-operativity while causing only minor effects on nucleotide-binding affinity and co-operativity. However, the substitution reversed the effect of diadenosine tetraphosphate, abolishing kinetic co-operativity in wild-type dhPPase, but restoring it in the variant dhPPase. A reverse serine-to-asparagine replacement restored kinetic co-operativity in ehPPase. Molecular dynamics simulations revealed that the asparagine substitution resulted in a change in the hydrogen-bonding pattern around the asparagine residue and the subunit interface, allowing greater flexibility at the subunit interface without a marked effect on the overall structure. These findings identify this asparagine residue as lying at the ‘crossroads’ of information paths connecting catalytic and regulatory domains within a subunit and catalytic sites between subunits.

scholarly journals CBS domains form energy-sensing modules whose binding of adenosine ligands is disrupted by disease mutations

2004 ◽  
Vol 113 (2) ◽  
pp. 274-284 ◽  
Author(s):  
John W. Scott ◽  
Simon A. Hawley ◽  
Kevin A. Green ◽  
Miliea Anis ◽  
Greg Stewart ◽  
...  
Keyword(s):  
Disease Mutations ◽  
Energy Sensing ◽  
Cbs Domains

Two sites for adenine-nucleotide regulation of ATP-sensitive potassium channels in mouse pancreatic ?-cells and HIT cells

1992 ◽  
Vol 129 (3) ◽  
Author(s):  
WilliamF. Hopkins ◽  
Sahba Fatherazi ◽  
Bettina Peter-Riesch ◽  
BarbaraE. Corkey ◽  
DanielL. Cook
Keyword(s):  
Potassium Channels ◽  
Adenine Nucleotide ◽  
Pancreatic Cells ◽  
Nucleotide Regulation ◽  
Hit Cells

scholarly journals Nucleotide regulation of heat-stable enterotoxin receptor binding and of guanylate cyclase activation

1992 ◽  
Vol 283 (3) ◽  
pp. 727-735 ◽  
Author(s):  
L C Katwa ◽  
C D Parker ◽  
J K Dybing ◽  
A A White
Keyword(s):  
Guanylate Cyclase ◽  
Single Phase ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Inhibitory Effects ◽  
Nucleotide Analogues ◽  
Heat Stable ◽  
Low Concentrations ◽  
Nucleotide Regulation ◽  
Guanylate Cyclase Activation

Certain nucleotides were found to regulate the binding of the Escherichia coli heat-stable enterotoxin (STa) to its receptor in pig intestinal brush border membranes. ATP and adenine nucleotide analogues inhibited 125I-STa binding, while guanine nucleotide analogues stimulated binding, with maximal effects at 0.5-1.0 mM. The strongest inhibitors were adenosine 5′-[beta gamma-imido]triphosphate (App[NH]p) (36%) and adenosine 5′-[beta-thio]diphosphate (ADP[S]) (41%). Inhibition did not require Mg2+, and was blocked by p-chloromercuribenzenesulphonate (PCMBS). Stimulation of binding required Mg2+, was not prevented by PCMBS and was maximal with GDP[S] (41%). While App[NH]p and MgGDP[S] appeared to be acting at different sites, they also interfered with each other. These nucleotides exerted only inhibitory effects on STa-stimulated guanylate cyclase activity, in contrast with the stimulatory effects of adenine nucleotides on atrial natriuretic peptide (ANP)-stimulated guanylate cyclase. Inhibition by low concentrations of MgApp[NH]p and MgATP was weaker above 0.1 mM, while MgGDP[S] and magnesium guanosine 5′-[gamma-thio]triphosphate (MgGTP[S]) inhibited in a single phase. Inhibition by MgApp[NH]p, at all concentrations, was competitive with the substrate (MgGTP), as was that by MgGDP[S] and MgGTP[S]. Whereas membrane guanylate cyclases usually show positively co-operative kinetics with respect to the substrate, STa-stimulated activity exhibited Michaelis-Menten kinetics with respect to MgGTP. This changed to positive co-operativity when Lubrol PX was the activator, or when the substrate was MnGTP. These results suggest the presence of both a regulatory and a catalytic nucleotide-binding site, which do not interact co-operatively with STa activation.

Heterogeneous Expression of Protein C (PC), Protein S (PS) and Thrombomodulin (TM) in Human Colon Cancer Tissue.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4037-4037
Author(s):  
Marek Wojtukiewicz ◽  
Ewa Sierko ◽  
Roman J. Zawadzki ◽  
Lech Zimnoch ◽  
Walter Klsiel
Keyword(s):  
Colon Cancer ◽  
Tumor Progression ◽  
Cancer Cells ◽  
Protein C ◽  
Protein S ◽  
Cancer Tissue ◽  
Colon Cancer Tissue ◽  
System Components ◽  
Heterogeneous Expression ◽  
Weak Expression

Abstract Colon cancer is often complicated by thromboembolic episodes. It has been recognized that blood coagulation proteins play a role in malignant tumor progression and metastatic dissemination. An important inhibitory mechanism is provided by protein C (PC) system consisting of protein C, protein S (PS) and thrombomodulin (TM). Thrombin binds to membrane-bound TM and consequently activates PC. Active PC together with its cofactor - PS inactivates coagulation factors Va and VIIIa. Recently novel biological activities have been desribed for protein C system components that do not relate to its hemostatic functions. Active protein C exerts antiapoptotic activity towards endothelial cells (ECs) and activates proteolytic enzymes. It induces proliferation of ECs and angiogenesis. Protein S was documented to inhibit apoptosis as well as inflammatory and immunologic response. The purpose of the study was to elucidate the solid phase interactions between colon cancer tissue and components of protein C system that may contribute to tumor progression. The tissues from colon cancer were obtained at surgical resection during radical treatment of 66 patients. The patients undergoing surgery have not received any previous anticancer therapy. Tumor fragments were processed acc. to AMeX method and than embedded in paraffin. Immunohistochemical studies (avidin-biotin complex-ABC - technique) were performed using polyclonal antibodies against PC, PS and TM. Weak expression of PC was observed in cancer cells of two thirds of the examined specimens while in 4/66 cases there was no staining for PC in cancer cell bodies. One third of colon cancer fragments revealed strong expression of PC. Presence of PS was demonstrated in 64 cases of colon cancer, however its expression was irregular: a weak staining was observed in 60 cases and strong one - only in 4 cases. Two cases of colon cancer tissue have not revealed any staining for PS in cancer cells. Weak expression of TM was observed in two thirds of the examined cases, while a strong staining was revealed in one third of colon cancer tissues. However the expression of TM was inconsistent: not all cell bodies were TM-positive. The presence of PC and PS, but not TM was demonstrated in tumor associated macrophages. Furthermore, PS and TM antigens were localized in tumor stroma. Heterogeneous expression of PC system components in colon cancer tissue may indicate that their biological activity, exerted via their interplay with coagulation/fibrinolysis and regardless of their function in hemostasis, may modulate tumor growth.

scholarly journals Visualizing Adenine Nucleotide Regulation of the KATP Channel

2018 ◽  
Vol 114 (3) ◽  
pp. 25a-26a
Author(s):  
Samuel G. Usher ◽  
Natascia Vedovato ◽  
Michael C. Puljung ◽  
Frances M. Ashcroft
Keyword(s):  
Katp Channel ◽  
Adenine Nucleotide ◽  
Nucleotide Regulation
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