The emerging role of calcium-dependent exocytosis in ATP release from nonexcitable cells

2005 ◽  
pp. 21-22 ◽  
Author(s):  
Ryszard Grygorczyk ◽  
Francis Boudreault
Keyword(s):  
Atp Release ◽  
Calcium Dependent

Collagen-Induced Platelet Aggregation: -Evidence Against the Essential Role of Platelet Adenosine Diphosphate

1979 ◽  
Vol 42 (04) ◽  
pp. 1193-1206 ◽  
Author(s):  
Barbara Nunn
Keyword(s):  
Platelet Aggregation ◽  
Time Course ◽  
Essential Role ◽  
Atp Release ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
High Doses ◽  
Induced Aggregation

SummaryThe hypothesis that platelet ADP is responsible for collagen-induced aggregation has been re-examined. It was found that the concentration of ADP obtaining in human PRP at the onset of aggregation was not sufficient to account for that aggregation. Furthermore, the time-course of collagen-induced release in human PRP was the same as that in sheep PRP where ADP does not cause release. These findings are not consistent with claims that ADP alone perpetuates a collagen-initiated release-aggregation-release sequence. The effects of high doses of collagen, which released 4-5 μM ADP, were not inhibited by 500 pM adenosine, a concentration that greatly reduced the effect of 300 μM ADP. Collagen caused aggregation in ADP-refractory PRP and in platelet suspensions unresponsive to 1 mM ADP. Thus human platelets can aggregate in response to collagen under circumstances in which they cannot respond to ADP. Apyrase inhibited aggregation and ATP release in platelet suspensions but not in human PRP. Evidence is presented that the means currently used to examine the role of ADP in aggregation require investigation.

Effect of Annexins Translocated in Extracellular Vesicles on Tumorigenesis

2020 ◽  
Vol 20 ◽  
Author(s):  
Qionghui Wu ◽  
Haidong Wei ◽  
Wenbo Meng ◽  
Xiaodong Xie ◽  
Zhenchang Zhang ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Extracellular Vesicles ◽  
Immune Cell ◽  
Epithelial Mesenchymal Transition ◽  
Main Role ◽  
Tumor Cell Adhesion ◽  
Mesenchymal Transition ◽  
Calcium Dependent ◽  
Tumor Neovascularization

: Annexin, a calcium-dependent phospholipid binding protein, can affect tumor cell adhesion, proliferation, apoptosis, invasion and metastasis, as well as tumor neovascularization in different ways. Recent studies have shown that annexin exists not only as an intracellular protein in tumor cells, but also in different ways to be secret outside the cell as a “crosstalk” tool for tumor cells and tumor microenvironment, thus playing an important role in the development of tumors, such as participating in epithelial-mesenchymal transition, regulating immune cell behavior, promoting neovascularization and so on. The mechanism of annexin secretion in the form of extracellular vesicles and its specific role is still unclear. This paper summarizes the main role of annexin secreted into the extracellular space in the form of extracellular vesicles in tumorigenesis and drug resistance and analyzes its possible mechanism.

scholarly journals Pannexins and Connexins: Their Relevance for Oocyte Developmental Competence

2021 ◽  
Vol 22 (11) ◽  
pp. 5918
Author(s):  
Paweł Kordowitzki ◽  
Gabriela Sokołowska ◽  
Marta Wasielak-Politowska ◽  
Agnieszka Skowronska ◽  
Mariusz T. Skowronski
Keyword(s):  
Assisted Reproductive Technologies ◽  
Mammalian Species ◽  
Atp Release ◽  
Reproductive Technologies ◽  
High Energy ◽  
Developmental Competence ◽  
Physiological Processes ◽  
Protein Group ◽  
Multicellular Organisms

The oocyte is the major determinant of embryo developmental competence in all mammalian species. Although fundamental advances have been generated in the field of reproductive medicine and assisted reproductive technologies in the past three decades, researchers and clinicians are still trying to elucidate molecular factors and pathways, which could be pivotal for the oocyte’s developmental competence. The cell-to-cell and cell-to-matrix communications are crucial not only for oocytes but also for multicellular organisms in general. This latter mentioned communication is among others possibly due to the Connexin and Pannexin families of large-pore forming channels. Pannexins belong to a protein group of ATP-release channels, therefore of high importance for the oocyte due to its requirements of high energy supply. An increasing body of studies on Pannexins provided evidence that these channels not only play a role during physiological processes of an oocyte but also during pathological circumstances which could lead to the development of diseases or infertility. Connexins are proteins that form membrane channels and gap-junctions, and more precisely, these proteins enable the exchange of some ions and molecules, and therefore they do play a fundamental role in the communication between the oocyte and accompanying cells. Herein, the role of Pannexins and Connexins for the processes of oogenesis, folliculogenesis, oocyte maturation and fertilization will be discussed and, at the end of this review, Pannexin and Connexin related pathologies and their impact on the developmental competence of oocytes will be provided.

scholarly journals The signaling role of extracellular ATP in co-culture of Shiraia sp. S9 and Pseudomonas fulva SB1 for enhancing hypocrellin A production

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xin Ping Li ◽  
Lu Lu Zhou ◽  
Yan Hua Guo ◽  
Jian Wen Wang
Keyword(s):  
Atp Release ◽  
Specific Inhibitor ◽  
Extracellular Atp ◽  
Oxidase Inhibitor ◽  
Disulfonic Acid ◽  
Early Event ◽  
Fungal Metabolites ◽  
Extracellular Signaling ◽  
Hypocrellin A

Abstract Background Adenosine 5′-triphosphate (ATP) plays both a central role as an intracellular energy source, and a crucial extracellular signaling role in diverse physiological processes of animals and plants. However, there are less reports concerning the signaling role of microbial extracellular ATP (eATP). Hypocrellins are effective anticancer photodynamic therapy (PDT) agents from bambusicolous Shiraia fungi. The co-culture of Shiraia sp. S9 and a bacterium Pseudomonas fulva SB1 isolated from Shiraia fruiting bodies was established for enhanced hypocrellin A (HA) production. The signaling roles of eATP to mediate hypocrellin biosynthesis were investigated in the co-culture. Results The co-culture induced release of eATP at 378 nM to the medium around 4 h. The eATP release was interdependent on cytosolic Ca2+ concentration and reactive oxygen species (ROS) production, respectively. The eATP production could be suppressed by the Ca2+ chelator EGTA or abolished by the channel blocker La3+, ROS scavenger vitamin C and NADPH oxidase inhibitor diphenyleneiodonium chloride (DPI). The bacterium-induced H2O2 production was strongly inhibited by reactive blue (RB), a specific inhibitor of membrane purinoceptors, but dependent on the induced Ca2+ influx in the co-culture. On the other hand, the application of exogenous ATP (exATP) at 10–300 µM to Shiraia cultures also promoted fungal conidiation and HA production, both of which were blocked effectively by the purinoceptor inhibitors pyridoxalphosphate-6-azophenyl-2′, 4′-disulfonic acid (PPADS) and RB, and ATP hydrolase apyrase. Both the induced expression of HA biosynthetic genes and HA accumulation were inhibited significantly under the blocking of the eATP or Ca2+ signaling, and the scavenge of ROS in the co-culture. Conclusions Our results indicate that eATP release is an early event during the intimate bacterial–fungal interaction and eATP plays a signaling role in the bacterial elicitation on fungal metabolites. Ca2+ and ROS are closely linked for activation of the induced ATP release and its signal transduction. This is the first report on eATP production in the fungal–bacterial co-culture and its involvement in the induced biosynthesis of fungal metabolites. Graphic abstract

scholarly journals A CACNA1A variant associated with trigeminal neuralgia alters the gating of Cav2.1 channels

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Eder Gambeta ◽  
Maria A. Gandini ◽  
Ivana A. Souza ◽  
Laurent Ferron ◽  
Gerald W. Zamponi
Keyword(s):  
Trigeminal Neuralgia ◽  
Missense Mutation ◽  
Neurotransmitter Release ◽  
Trigeminal System ◽  
Wild Type ◽  
Calcium Dependent ◽  
Whole Cell Patch Clamp ◽  
C Terminus ◽  
Dependent Inactivation

AbstractA novel missense mutation in the CACNA1A gene that encodes the pore forming α1 subunit of the CaV2.1 voltage-gated calcium channel was identified in a patient with trigeminal neuralgia. This mutation leads to a substitution of proline 2455 by histidine (P2455H) in the distal C-terminus region of the channel. Due to the well characterized role of this channel in neurotransmitter release, our aim was to characterize the biophysical properties of the P2455H variant in heterologously expressed CaV2.1 channels. Whole-cell patch clamp recordings of wild type and mutant CaV2.1 channels expressed in tsA-201 cells reveal that the mutation mediates a depolarizing shift in the voltage-dependence of activation and inactivation. Moreover, the P2455H mutant strongly reduced calcium-dependent inactivation of the channel that is consistent with an overall gain of function. Hence, the P2455H CaV2.1 missense mutation alters the gating properties of the channel, suggesting that associated changes in CaV2.1-dependent synaptic communication in the trigeminal system may contribute to the development of trigeminal neuralgia.

scholarly journals Role of Phosphopantetheinyl Transferase Genes in Antibiotic Production by Streptomyces coelicolor

2008 ◽  
Vol 190 (20) ◽  
pp. 6903-6908 ◽  
Author(s):  
Ya-Wen Lu ◽  
Adrianna K. San Roman ◽  
Amy M. Gehring
Keyword(s):  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Morphological Development ◽  
Phosphopantetheinyl Transferase ◽  
Calcium Dependent ◽  
Actinorhodin Production

ABSTRACT The phosphopantetheinyl transferase genes SCO5883 (redU) and SCO6673 were disrupted in Streptomyces coelicolor. The redU mutants did not synthesize undecylprodigiosin, while SCO6673 mutants failed to produce calcium-dependent antibiotic. Neither gene was essential for actinorhodin production or morphological development in S. coelicolor, although their mutation could influence these processes.

Role of calcium-dependent actin-bundling proteins: Characterization ofDictyosteliummutants lacking fimbrin and the 34-kilodalton protein

2005 ◽  
Vol 62 (4) ◽  
pp. 210-231 ◽  
Author(s):  
Claudia Pikzack ◽  
Josef Prassler ◽  
Ruth Furukawa ◽  
Marcus Fechheimer ◽  
Francisco Rivero
Keyword(s):  
Calcium Dependent

scholarly journals PQQ-Aza-Crown Ether Complexes as Biomimetics for Lanthanide and Calcium Dependent Alcohol Dehydrogenases

2021 ◽  
Author(s):  
Violeta A. Vetsova ◽  
Katherine R. Fisher ◽  
Henning Lumpe ◽  
Alexander Schäfer ◽  
Erik K. Schneider ◽  
...  
Keyword(s):  
Metal Ions ◽  
Gas Phase ◽  
Ion Mobility ◽  
Paramagnetic Resonance ◽  
Calcium Dependent ◽  
Lower Charge ◽  
Crown Ether Complexes ◽  
Recent Group ◽  
Electron Paramagnetic

<div>Understanding the role of metal ions in biology can lead to the development of new catalysts for</div><div>several industrially important transformations. Lanthanides are the most recent group of metal ions</div><div>that have been shown to be important in biology i.e. - in quinone-dependent methanol</div><div>dehydrogenases (MDH). Here we evaluate a pyrroloquinoline quinone and 1-aza-15-crown-5 based</div><div>ligand platform as scaffold for Ca2+ , Ba2+ , La3+ and Lu3+ biomimetics of MDH and we evaluate the</div><div>importance of ligand design, charge, size, counterions and base for the alcohol oxidation reaction</div><div>using NMR spectroscopy. In addition, we report a new straightforward synthetic route (3 steps</div><div>instead of 11 and 33% instead of 0.6% yield) for biomimetic ligands based on PQQ. We show that</div><div>when studying biomimetics for MDH, larger metal ions and those with lower charge in this case</div><div>promote the dehydrogenation reaction more effectively and that this is likely an effect of the ligand</div><div>design which must be considered when studying biomimetics. To gain more information on the</div><div>structures and impact of counterions of the complexes, we performed collision induced dissociation</div><div>(CID) experiments and observe that the nitrates are more tightly bound than the triflates. To resolve</div><div>the structure of the complexes in the gas phase we combined DFT-calculations and ion mobility</div><div>measurements (IMS). Furthermore, we characterized the obtained complexes and reaction mixtures</div><div>using Electron Paramagnetic Resonance (EPR) spectroscopy and show the emergence of a quinone-</div><div>based radical during the reaction with substrate and base.</div>

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