-
Function (Oxford, England) 2023
Topics: Oxidative Phosphorylation; Adenosine Triphosphate
PubMed: 37799324
DOI: 10.1093/function/zqad051 -
Nucleic Acids Research Nov 2020Mfd-dependent transcription termination plays an important role in transcription-coupled DNA repair, transcription-replication conflict resolution, and antimicrobial...
Mfd-dependent transcription termination plays an important role in transcription-coupled DNA repair, transcription-replication conflict resolution, and antimicrobial resistance development. Despite extensive studies, the molecular mechanism of Mfd-dependent transcription termination in bacteria remains unclear, with several long-standing puzzles. How Mfd is activated by stalled RNA polymerase (RNAP) and how activated Mfd translocates along the DNA are unknown. Here, we report the single-particle cryo-electron microscopy structures of T. thermophilus Mfd-RNAP complex with and without ATPγS. The structures reveal that Mfd undergoes profound conformational changes upon activation, contacts the RNAP β1 domain and its clamp, and pries open the RNAP clamp. These structures provide a foundation for future studies aimed at dissecting the precise mechanism of Mfd-dependent transcription termination and pave the way for rational drug design targeting Mfd for the purpose of tackling the antimicrobial resistance crisis.
Topics: Adenosine Triphosphate; Bacterial Proteins; Cryoelectron Microscopy; DNA, Bacterial; DNA-Directed RNA Polymerases; Models, Molecular; Thermus thermophilus; Transcription Factors; Transcription Termination, Genetic
PubMed: 33068413
DOI: 10.1093/nar/gkaa904 -
BMC Medicine Mar 2023Mitochondrial transplantation (MTx) is an emerging but poorly understood technology with the potential to mitigate severe ischemia-reperfusion injuries after cardiac...
BACKGROUND
Mitochondrial transplantation (MTx) is an emerging but poorly understood technology with the potential to mitigate severe ischemia-reperfusion injuries after cardiac arrest (CA). To address critical gaps in the current knowledge, we test the hypothesis that MTx can improve outcomes after CA resuscitation.
METHODS
This study consists of both in vitro and in vivo studies. We initially examined the migration of exogenous mitochondria into primary neural cell culture in vitro. Exogenous mitochondria extracted from the brain and muscle tissues of donor rats and endogenous mitochondria in the neural cells were separately labeled before co-culture. After a period of 24 h following co-culture, mitochondrial transfer was observed using microscopy. In vitro adenosine triphosphate (ATP) contents were assessed between freshly isolated and frozen-thawed mitochondria to compare their effects on survival. Our main study was an in vivo rat model of CA in which rats were subjected to 10 min of asphyxial CA followed by resuscitation. At the time of achieving successful resuscitation, rats were randomly assigned into one of three groups of intravenous injections: vehicle, frozen-thawed, or fresh viable mitochondria. During 72 h post-CA, the therapeutic efficacy of MTx was assessed by comparison of survival rates. The persistence of labeled donor mitochondria within critical organs of recipient animals 24 h post-CA was visualized via microscopy.
RESULTS
The donated mitochondria were successfully taken up into cultured neural cells. Transferred exogenous mitochondria co-localized with endogenous mitochondria inside neural cells. ATP content in fresh mitochondria was approximately four times higher than in frozen-thawed mitochondria. In the in vivo survival study, freshly isolated functional mitochondria, but not frozen-thawed mitochondria, significantly increased 72-h survival from 55 to 91% (P = 0.048 vs. vehicle). The beneficial effects on survival were associated with improvements in rapid recovery of arterial lactate and glucose levels, cerebral microcirculation, lung edema, and neurological function. Labeled mitochondria were observed inside the vital organs of the surviving rats 24 h post-CA.
CONCLUSIONS
MTx performed immediately after resuscitation improved survival and neurological recovery in post-CA rats. These results provide a foundation for future studies to promote the development of MTx as a novel therapeutic strategy to save lives currently lost after CA.
Topics: Rats; Animals; Cardiopulmonary Resuscitation; Heart Arrest; Mitochondria; Brain; Adenosine Triphosphate; Disease Models, Animal
PubMed: 36922820
DOI: 10.1186/s12916-023-02759-0 -
Journal of the American Chemical Society Jan 2023The self-assembly of surfactant-based structures that rely for their formation on the combination of a thermodynamically controlled and a dissipative pathway is...
The self-assembly of surfactant-based structures that rely for their formation on the combination of a thermodynamically controlled and a dissipative pathway is described. Adenosine triphosphate (ATP) acts as a high-affinity template and triggers assembly formation at low surfactant concentrations. The presence of these assemblies creates the conditions for the activation of a dissipative self-assembly process by a weak-affinity substrate. The substrate-induced recruitment of additional surfactants leads to the spontaneous formation of catalytic hotspots in the ATP-stabilized assemblies that cleave the substrate. As a result of the two self-assembly processes, catalysis can be observed at a surfactant concentration at which low catalytic activity is observed in the absence of ATP.
Topics: Adenosine Triphosphate; Surface-Active Agents; Catalysis
PubMed: 36576874
DOI: 10.1021/jacs.2c09343 -
Molecular Cell Aug 2010Molecular chaperones assist folding processes and conformational changes in many proteins. In order to do so, they progress through complex conformational cycles... (Review)
Review
Molecular chaperones assist folding processes and conformational changes in many proteins. In order to do so, they progress through complex conformational cycles themselves. In this review, I discuss the diverse conformational dynamics of the ATP-dependent chaperones of the Hsp60, Hsp70, Hsp90, and Hsp100 families.
Topics: Adenosine Triphosphate; Animals; Heat-Shock Proteins; Humans; Protein Conformation
PubMed: 20705236
DOI: 10.1016/j.molcel.2010.07.012 -
Purinergic Signalling Jun 2024Activation of the ATP-gated P2X7 receptor (P2X7R), implicated in numerous diseases of the brain, can trigger diverse responses such as the release of pro-inflammatory...
Activation of the ATP-gated P2X7 receptor (P2X7R), implicated in numerous diseases of the brain, can trigger diverse responses such as the release of pro-inflammatory cytokines, modulation of neurotransmission, cell proliferation or cell death. However, despite the known species-specific differences in its pharmacological properties, to date, most functional studies on P2X7R responses have been analyzed in cells from rodents or immortalised cell lines. To assess the endogenous and functional expression of P2X7Rs in human astrocytes, we differentiated human-induced pluripotent stem cells (hiPSCs) into GFAP and S100 β-expressing astrocytes. Immunostaining revealed prominent punctate P2X7R staining. P2X7R protein expression was also confirmed by Western blot. Importantly, stimulation with the potent non-selective P2X7R agonist 2',3'-O-(benzoyl-4-benzoyl)-adenosine 5'- triphosphate (BzATP) or endogenous agonist ATP induced robust calcium rises in hiPSC-derived astrocytes which were blocked by the selective P2X7R antagonists AFC-5128 or JNJ-47965567. Our findings provide evidence for the functional expression of P2X7Rs in hiPSC-derived astrocytes and support their in vitro utility in investigating the role of the P2X7R and drug screening in disorders of the central nervous system (CNS).
Topics: Receptors, Purinergic P2X7; Humans; Astrocytes; Induced Pluripotent Stem Cells; Adenosine Triphosphate; Cell Differentiation; Cells, Cultured; Purinergic P2X Receptor Antagonists
PubMed: 37453017
DOI: 10.1007/s11302-023-09957-8 -
Science Signaling Jan 2010Cells release adenosine triphosphate (ATP), which activates plasma membrane-localized P2X and P2Y receptors and thereby modulates cellular function in an autocrine or... (Review)
Review
Cells release adenosine triphosphate (ATP), which activates plasma membrane-localized P2X and P2Y receptors and thereby modulates cellular function in an autocrine or paracrine manner. Release of ATP and the subsequent activation of P2 receptors help establish the basal level of activation (sometimes termed "the set point") for signal transduction pathways and regulate a wide array of responses that include tissue blood flow, ion transport, cell volume regulation, neuronal signaling, and host-pathogen interactions. Basal release and autocrine or paracrine responses to ATP are multifunctional, evolutionarily conserved, and provide an economical means for the modulation of cell, tissue, and organismal biology.
Topics: Adenosine Triphosphate; Animals; Autocrine Communication; Biological Transport; Cell Size; Humans; Models, Biological; Paracrine Communication; Receptors, Purinergic P2; Receptors, Purinergic P2X; Receptors, Purinergic P2Y12
PubMed: 20068232
DOI: 10.1126/scisignal.3104re1 -
FEBS Letters Nov 1987We found 8-azidoadenosine 5'-diphosphate to be a phosphoryl acceptor in the enzymatic conversion of 1,3-diphosphoglyceric acid to 3-phosphoglycerate. This has allowed us...
We found 8-azidoadenosine 5'-diphosphate to be a phosphoryl acceptor in the enzymatic conversion of 1,3-diphosphoglyceric acid to 3-phosphoglycerate. This has allowed us to synthesize in a single-step procedure carrier-free 8-azidoadenosine 5'-[gamma-32P]triphosphate, requiring no further purification of the end product. The synthesized 8-azidoadenosine 5'-[gamma-32P]triphosphate has been characterized and shown to meet all the criteria for a specific photoreactive ATP analogue.
Topics: Adenosine Triphosphate; Affinity Labels; Azides; Kinetics; Sodium-Potassium-Exchanging ATPase
PubMed: 2824239
DOI: 10.1016/0014-5793(87)80432-5 -
American Journal of Surgery Jun 2010Small unilamellar lipid vesicles were used to encapsulate adenosine triphosphate (ATP-vesicles) for intracellular energy delivery and were tested for diabetic skin...
BACKGROUND
Small unilamellar lipid vesicles were used to encapsulate adenosine triphosphate (ATP-vesicles) for intracellular energy delivery and were tested for diabetic skin wounds in rabbits.
METHODS
Diabetes was induced by alloxan. The mean peak blood glucose concentration was 505 mg/dL. One ear was made ischemic and 80 full-thickness wounds were created in 10 animals. ATP-vesicles or saline was used and healing was compared.
RESULTS
On the non-ischemic ears, mean closure time for ATP-vesicles-treated wounds was 13.7 days versus 16.4 days for saline-treated wounds (P < .05). On the ischemic ears, mean closure time for ATP-vesicles-treated wounds was 15.3 days versus 19.3 days for saline-treated wounds (P < .01). Histological study indicated better healing and re-epithelialization in the ATP-vesicles-treated wounds.
CONCLUSIONS
Intracellular delivery of ATP accelerated the healing process of diabetic skin wounds on ischemic and non-ischemic rabbit ears. The mechanisms deserve further study but may be related to improved cellular energy supplies.
Topics: Adenosine Triphosphate; Analysis of Variance; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Drug Delivery Systems; Intracellular Space; Rabbits; Skin; Unilamellar Liposomes; Wound Healing
PubMed: 20609726
DOI: 10.1016/j.amjsurg.2009.05.040 -
Molecules (Basel, Switzerland) Dec 2020The use of fluorescent probes in a multitude of applications is still an expanding field. This review covers the recent progress made in small molecular, spirocyclic... (Review)
Review
The use of fluorescent probes in a multitude of applications is still an expanding field. This review covers the recent progress made in small molecular, spirocyclic xanthene-based probes containing different heteroatoms (e.g., oxygen, silicon, carbon) in position 10'. After a short introduction, we will focus on applications like the interaction of probes with enzymes and targeted labeling of organelles and proteins, detection of small molecules, as well as their use in therapeutics or diagnostics and super-resolution microscopy. Furthermore, the last part will summarize recent advances in the synthesis and understanding of their structure-behavior relationship including novel computational approaches.
Topics: Adenosine Triphosphate; Animals; Fluorescent Dyes; Humans; Microscopy, Fluorescence; Neoplasms; Photosensitizing Agents; Spiro Compounds; Structure-Activity Relationship; Xanthenes
PubMed: 33339370
DOI: 10.3390/molecules25245964