MscL is multimeric protein that forms a large conductance mechanosensitive channel in the inner membrane of Escherichia coli. Since gated by tension transmitted through lipid bilayer, we have been able to measure its gating parameters as function absolute tension. Using purified reconstituted liposomes, recorded single currents and varied pressure gradient (P) vary (T). The was calculated from P radius curvature obtained using video microscopy patch. probability being open (Po) has steep...

Heart rate and contractility are sensitive to stretch. To better understand the origin of these effects, we have studied effect mechanical stimuli on a model system tissue-cultured heart cells. Gently prodding cells with pipette produced Ca2+ influx that often led waves calcium-induced calcium release (CICR) spreading from site stimulation. could also be by pulling neighboring The response was blocked removing extracellular or adding 20 microM Gd3+ normal saline. sensitivity probably arose...

Stretch-activated ion channels of animal, plant, bacterial, and fungal cells are implicated in mechanotransduction osmoregulation. A new class channel has now been described that is stretch-inactivated. These occur neurons, where they coexist with stretch-activated channels. Both potassium selective. The differing stretch sensitivities the two minimize conductance over an intermediate range tension, consequence that, this same range, voltage-gated calcium most readily opened. Thus, by...

During dental plaque formation, the interaction of different organisms is important in development complex communities. Fusobacterium nucleatum considered a ‘bridge‐organism’ that facilitates colonization other bacteria by coaggregation‐mediated mechanisms and possibly making environment conducive for oxygen intolerant anaerobes. These studies were carried out to determine whether coaggregation between F. Tannerella forsythia formation mixed species biofilms. Further, role BspA protein,...

ABSTRACT Heart ventricle cells of Lymnaea stagnalis contain a stretch-activated K+ channel which exhibits two open states and three closed states. Over the range 0 to –25 mmHg (1 = 133·3 Pa), probability that is steeply non-linear function negative pressure. Pressure-dependent decreases in mean times longest component closed-time distribution are observed same (because other show no consistent or sufficiently large changes with pressure) assumed account for increases being open. Channel...

1. The voltage dependence of binding and gating in wild‐type mutant recombinant mouse nicotinic acetylcholine receptors (AChRs) was examined at the single‐channel level. 2. closing rate constant diliganded decreased e‐fold with approximately 66 mV hyperpolarization both (adult embryonic) receptors. opening a receptor (alpha Y93F) not dependent. 3. monoliganded several having mutation site G153S) or pore region L251C epsilon T264P). these 124 hyperpolarization. 4. unliganded two Neither nor...

In first-passage human umbilical vein endothelial cells (HUVEC) and bovine aortic (passages 13–16), exposure to gentle mechanical perturbation using a micropipette caused transient rise in intracellular calcium concentration ([Ca2+]i). The increase ([Ca2+]) occurred each time the cell was nudged. Three responses were evoked of 27 5 independent HUVEC harvests. Increase [Ca2+] returned near baseline levels within approximately 30 s. stimulus did not cause membrane puncture, as indicated by 1)...

Hypotonic cell swelling triggers an increase in intracellular Ca2+ concentration that is deemed responsible for the subsequent regulated volume decrease many cells. To understand mechanisms underlying this increase, we have studied sources contribute to hypotonic swelling-induced (HICI) GH3 Fura 2 fluorescence of populations revealed extracellular, but not intracellular, stores were required. HICI was abolished by nifedipine, a blocker L-type channels, and Gd3+, nonspecific stretch-activated...

Abstract IL-17 is the hallmark cytokine of newly described “Th17” lymphocyte population. The composition, subunit dynamics, and ligand contacts receptor are poorly defined. We previously demonstrated that IL-17RA oligomerizes in membrane without a ligand. In this study, computational modeling identified two fibronectin-III-like (FN) domains connected by nonstructured linker, which we predicted to mediate homotypic interactions. yeast two-hybrid, membrane-proximal FN domain (FN2), but not...

Abstract Background Myeloid-derived Suppressor Cells (MDSC) have been identified as tumor-induced immature myeloid cells (IMC) with potent immune suppressive activity in cancer. Whereas strict phenotypic classification of MDSC has challenging due to the highly heterogeneous nature cell surface marker expression, use functional markers such Arginase and inducible nitric oxide synthase (iNOS) may represent a better categorization strategy. In this study we investigated whether iNOS could be...

By binding to the adaptor protein SKP1 and serving as substrate receptors for Cullin, F-box E3 ubiquitin ligase complex, proteins regulate critical cellular processes including cell cycle progression membrane trafficking. While are conserved throughout eukaryotes well studied in yeast, plants, animals, studies parasitic protozoa lagging. We have identified eighteen putative Toxoplasma genome of which four predicted homologs Plasmodium. Two were demonstrated be important fitness here we focus...

Prenatal ethanol exposure (PE) impairs midbrain dopaminergic (DA) neuron function, which might contribute to various cognitive and behavioral deficits, including attention deficits increased addiction risk, often observed in individuals with fetal alcohol spectrum disorders. Currently, the underlying mechanisms for PE-induced are unclear. PE could lead neuroinflammation by activating microglia, play an important role synaptic function. In present study, we investigated effects on microglial...

We sought to evaluate the mechanisms by which mechanical perturbation elevates intracellular calcium in endothelial cells. report that transient elevation cultured bovine aortic cells (BAEC) response gentle with side of a micropipette was not blocked depolarization (external K+, 130 mmol/L), nifedipine (10 mumol/L), or Bay K 8644 R(+) mumol/L). Thus, voltage-dependent channels were involved response. Also, amiloride mumol/L) and tetraethylammonium (1 mmol/L) had no effect on mobilization,...

Tubules may arise during branching morphogenesis through several mechanisms including wrapping, budding, cavitation and cord hollowing. In this report we present evidence that is consistent with renal proximal tubule formation a process of hollowing (a requires the concomitant establishment apicobasal polarity lumen formation). Pockets filled Lucifer Yellow were observed within developing cords rabbit cells in matrigel. The observation accumulation suggests functional polarization. initially...

The microtubule (MT)-associated DCX protein plays an essential role in the development of mammalian cerebral cortex. We report on identification a kinase, doublecortin kinase-2 (DCK2), with domain (DC) highly homologous to DCX. DCK2 has MT binding activity associated its DC and kinase mediated by domain, organized structure which two domains are functionally independent. Overexpression stabilizes cytoskeleton against cold-induced depolymerization. Autophosphorylation strongly reduces...

Abstract At least nine neurodegenerative disorders are caused by expansion of polyglutamine repeats in various genes. This induces the formation nuclear inclusions (NI) within cell types. In this study, we developed a model for diseases using primary cultures sympathetic neurons from superior cervical ganglia prenatal rat pups. Transfection with plasmid encoding 127 glutamine causes NI to develop ∼70% 6 days. addition, it somatic atrophy and inhibits dendritic growth. The NIs contain...

Mitochondrial malfunction is a hallmark of many diseases, including neurodegenerative disorders, cardiovascular and lung cancers. We previously found that alveolar progenitor cells, which are more resistant to cigarette smoke-induced injury than the other cells parenchyma, upregulate mtDNA-encoded small non-coding RNA mito-ncR-805 after exposure smoke. The acts as retrograde signal between mitochondria nucleus. Here, we identified region conserved in mammalian mitochondrial genomes generated...

Mebendazole-resistant mutants of Caenorhabditis elegans were isolated following mutagenesis the wild-type strain, N2, with ethylmethane sulphonate. The define a single autosomal gene and are allelic to ben-1. They grow, move, reproduce normally in presence mebendazole cross-resistant albendazole, cambendazole, fenbendazole, methylbenzimidazole carbamate, thiabendazole. Accumulations membrane-bound, electron-dense material associated nervous tissue cells seen electron micrographs L3, L4,...

An improved method for the fixation of third and fourth larval stages adults Caenorhabditis clegans has been developed. Worms are placed in a mixture 1.5% paraformaldehyde 1.0% glutaraldehyde at pH 7.0 70 C suspension promptly cooled water bath 20 1 hr. The fixed worms then immersed 5% hydrogen peroxide 4 hr, stained en bloc uranyl acetate, embedded resin electron microscopy. procedure results superior fixation, particularly micro filaments tubules. high temperature initial straightens thus...

Curare action on nicotinic acetylcholine receptors has a number of facets, which the best known is competitive antagonism. Here we describe weak agonist 10 −5 M curare murine skeletal muscle cell line, G8. Although induces no depolarization in G8 cells, single-channel recordings reveal short-lived curare-induced currents. A feature these brief events multiplicity conductance levels (of four with conductances 48, 37, 14, and 6 pS, none had lifetime greater than 1.5 ms). Most well-resolved...