Presynaptic Ca(2+) influx at the inhibitor of the crayfish neuromuscular junction: a photometric study at a high time resolution.
AuthorsVyshedskiy A, Lin JW
JournalJ Neurophysiol
PubMed ID10634895
'Presynaptic calcium influx at the inhibitor of the crayfish neuromuscular junction was investigated by measuring fluorescence transients generated by calcium-sensitive dyes. This approach allowed us to correlate presynaptic calcium influx with transmitter release at a high time resolution. Systematic testing of the calcium indicators showed that only low-affinity dyes, with ... More
Requirement for an additional divalent metal cation to activate protein tyrosine kinases.
AuthorsSun G, Budde RJ
JournalBiochemistry
PubMed ID9047313
'In addition to the magnesium ion needed to form the true phosphate-donating substrate (ATP-Mg complex), we have determined that at least one additional Mg2+ ion is essential for the activation of protein tyrosine kinases. This activation was investigated in detail using purified Csk, Src, and the fibroblast growth factor receptor ... More
Ca2+ fluorescence imaging with pico- and femtosecond two-photon excitation: signal and photodamage.
AuthorsKoester HJ, Baur D, Uhl R, Hell SW
JournalBiophys J
PubMed ID10512842
'The signal and limitations of calcium florescence imaging using nonresonant multiphoton absorption of near-infrared femto- and picosecond laser pulses were examined. The fluorescence changes of various Ca(2+)-indicators induced by transient increases of the intradendritic calcium concentration were evaluated by evoking physiological activity in neocortical neurons in rat brain slices. Photodamage ... More
Effects of magnesium on cyclic GMP hydrolysis by the bovine retinal rod cyclic GMP phosphodiesterase.
AuthorsSrivastava D, Fox DA, Hurwitz RL
JournalBiochem J
PubMed ID7772055
'Knowledge of the kinetics of the rod cyclic GMP phosphodiesterase is essential for understanding the kinetics and gain of the light response. Therefore, the interactions between Mg2+, cyclic GMP, and purified, trypsin-activated bovine rod cyclic GMP phosphodiesterase (EC 3.1.4.17) were examined. The effects of Mg2+ and of cyclic GMP on ... More
Mechanisms of calcium influx into hippocampal spines: heterogeneity among spines, coincidence detection by NMDA receptors, and optical quantal analysis.
AuthorsYuste R, Majewska A, Cash SS, Denk W
JournalJ Neurosci
PubMed ID10066251
'Dendritic spines receive most excitatory inputs in the vertebrate brain, but their function is still poorly understood. Using two-photon calcium imaging of CA1 pyramidal neurons in rat hippocampal slices, we investigated the mechanisms by which calcium enters into individual spines in the stratum radiatum. We find three different pathways for ... More
Coupling of calcium homeostasis to axonal sodium in axons of mouse optic nerve.
AuthorsVerbny Y, Zhang CL, Chiu SY
JournalJ Neurophysiol
PubMed ID12163532
'Axonal populations in neonatal and mature optic nerves were selectively stained with calcium dyes for analysis of calcium homeostasis and its possible coupling to axonal Na. Repetitive nerve stimulation causes a rise in axonal [Ca(2+)](i) the posttetanus recovery of which is impeded by increasing the number of action potentials in ... More
Optical measurement of presynaptic calcium currents.
AuthorsSabatini BL, Regehr WG
JournalBiophys J
PubMed ID9512051
'Measurements of presynaptic calcium currents are vital to understanding the control of transmitter release. However, most presynaptic boutons in the vertebrate central nervous system are too small to allow electrical recordings of presynaptic calcium currents (I(Ca)pre). We therefore tested the possibility of measuring I(Ca)pre optically in boutons loaded with calcium-sensitive ... More
Presynaptic strontium dynamics and synaptic transmission.
AuthorsXu-Friedman MA, Regehr WG
JournalBiophys J
PubMed ID10096899
'Strontium can replace calcium in triggering neurotransmitter release, although peak release is reduced and the duration of release is prolonged. Strontium has therefore become useful in probing release, but its mechanism of action is not well understood. Here we study the action of strontium at the granule cell to Purkinje ... More
NMDA receptor-mediated subthreshold Ca(2+) signals in spines of hippocampal neurons.
AuthorsKovalchuk Y, Eilers J, Lisman J, Konnerth A
JournalJ Neurosci
PubMed ID10684880
'We have used rapid confocal microscopy to investigate the mechanism of Ca(2+) signals in individual dendritic spines of hippocampal CA1 pyramidal cells. The experiments focused on the signals that occur during single weak synaptic responses that were subthreshold for triggering postsynaptic action potentials. These Ca(2+) signals were not strongly affected ... More
Fluorescence changes of genetic calcium indicators and OGB-1 correlated with neural activity and calcium in vivo and in vitro.
AuthorsHendel T, Mank M, Schnell B, Griesbeck O, Borst A, Reiff DF,
JournalJ Neurosci
PubMed ID18632944
'Recent advance in the design of genetically encoded calcium indicators (GECIs) has further increased their potential for direct measurements of activity in intact neural circuits. However, a quantitative analysis of their fluorescence changes (DeltaF) in vivo and the relationship to the underlying neural activity and changes in intracellular calcium concentration ... More
Identification of the magnesium-binding domain of the high-affinity ATP-binding site of the Bacillus subtilis and Escherichia coli SecA protein.
Authorsvan der Wolk JP, Klose M, de Wit JG, den Blaauwen T, Freudl R, Driessen AJ
JournalJ Biol Chem
PubMed ID7642557
'The homodimeric SecA protein is the peripheral subunit of the translocase, and couples the hydrolysis of ATP to the translocation of precursor proteins across the bacterial cytoplasmic membrane. The high affinity ATP binding activity of SecA resides in the amino-terminal domain of SecA. This domain contains a tandem repeat of ... More
Photo-physical properties of Ca2+-indicator dyes suitable for two-photon fluorescence-lifetime recordings.
AuthorsWilms CD, Eilers J,
JournalJ Microsc
PubMed ID17371443
We analyzed the suitability of various Ca2+-indicator dyes for quantitative two-photon fluorescence-lifetime imaging. Although fura-2, fluo-3, BTC and calcein did not show useful Ca2+-dependent lifetime changes, calcium orange, calcium green-1, oregon green-2 and -5N, as well as magnesium green allowed to quantify the Ca2+-free and Ca2+-bound dye fractions by a ... More
The life cycle of Ca(2+) ions in dendritic spines.
AuthorsSabatini BL, Oertner TG, Svoboda K
JournalNeuron
PubMed ID11832230
Spine Ca(2+) is critical for the induction of synaptic plasticity, but the factors that control Ca(2+) handling in dendritic spines under physiological conditions are largely unknown. We studied [Ca(2+)] signaling in dendritic spines of CA1 pyramidal neurons and find that spines are specialized structures with low endogenous Ca(2+) buffer capacity ... More
A novel kinetic assay of mitochondrial ATP-ADP exchange rate mediated by the ANT.
A novel method exploiting the differential affinity of ADP and ATP to Mg(2+) was developed to measure mitochondrial ADP-ATP exchange rate. The rate of ATP appearing in the medium after addition of ADP to energized mitochondria, is calculated from the measured rate of change in free extramitochondrial [Mg(2+)] reported by ... More
Visual imaging of ion distribution in human epidermis.
AuthorsDenda M, Hosoi J, Asida Y
JournalBiochem Biophys Res Commun
PubMed ID10872816
The distribution of calcium, magnesium, potassium, sodium, and hydrogen ions in the human epidermis was visualized by blotting to gel containing chemical indicators and the effects of skin barrier disruption were examined. In normal skin, both calcium and magnesium were localized with high concentration in the upper epidermis. EDTA blocked ... More
Probing fundamental aspects of synaptic transmission with strontium.
AuthorsXu-Friedman MA, Regehr WG
JournalJ Neurosci
PubMed ID10844010
Strontium is capable of supporting synaptic transmission, but release is dramatically different from that evoked in calcium. By measuring presynaptic strontium levels, we gain insight into the actions of strontium, which has implications for the identification of molecules involved in different aspects of synaptic transmission. We examined presynaptic divalent levels ... More
Caffeine interaction with fluorescent calcium indicator dyes.
AuthorsMuschol M, Dasgupta BR, Salzberg BM
JournalBiophys J
PubMed ID10388782
We report that caffeine, in millimolar concentrations, interacts strongly with four common calcium indicator dyes: mag-fura-2, magnesium green, fura-2, and fluo-3. Fluorescence intensities are either noticeably enhanced (mag-fura-2, fura-2) or diminished (magnesium green, fluo-3). The caffeine-induced changes in the fluorescence spectra are clearly distinct from those of metal ion binding ... More
Mechanism and kinetics of heterosynaptic depression at a cerebellar synapse.
AuthorsDittman JS, Regehr WG
JournalJ Neurosci
PubMed ID9364051
High levels of activity at a synapse can lead to spillover of neurotransmitter from the synaptic cleft. This extrasynaptic neurotransmitter can diffuse to neighboring synapses and modulate transmission via presynaptic receptors. We studied such modulation at the synapse between granule cells and Purkinje cells in rat cerebellar slices. Brief tetanic ... More
Zinc permeates mouse muscle ACh receptor channels expressed in BOSC 23 cells and affects channel function.
AuthorsRagozzino D, Giovannelli A, Degasperi V, Eusebi F, Grassi F
JournalJ Physiol
PubMed ID11080253
1. The influx of Zn2+ through the channels of fetal and adult mouse muscle nicotinic acetylcholine receptors (gamma- and epsilon-AChRs) and its effects on receptor function were studied in transiently transfected human BOSC 23 cells, by combining patch-clamp recordings with digital fluorescence microscopy. 2. ACh-induced whole-cell currents were reversibly reduced ... More
In the previous sections we demonstrated imaging of intracellular Ca2+ using our approach to FLIM. What other analytes can be imaged using FLIM? We have now characterized the lifetime of a good number of ion indicators. Based on these studies we know that Cl- can be imaged using FLIM with ... More
Transcription factor NF-kappa B represses ANT1 transcription and leads to mitochondrial dysfunctions.
Authors
JournalSci Rep
PubMed ID28317877
Species-specific consequences of an E40K missense mutation in superoxide dismutase 1 (SOD1).
Authors
JournalFASEB J
PubMed ID31914665
Magnesium efflux from Drosophila Kenyon cells is critical for normal and diet-enhanced long-term memory.
Authors
JournalElife
PubMed ID33242000
Engineering Saccharomyces cerevisiae fatty acid composition for increased tolerance to octanoic acid.
Authors
JournalBiotechnol Bioeng
PubMed ID28294288
Disruption of Acetyl-Lysine Turnover in Muscle Mitochondria Promotes Insulin Resistance and Redox Stress without Overt Respiratory Dysfunction.
Authors
JournalCell Metab
PubMed ID31813822
Monitoring intracellular nanomolar calcium using fluorescence lifetime imaging.
Authors
JournalNat Protoc
PubMed ID29470463
Structural and functional properties of a magnesium transporter of the SLC11/NRAMP family.