Search results for "Transport system"
showing 10 items of 77 documents
The L-glutamate transporters GLAST (EAAT1) and GLT-1 (EAAT2): expression and regulation in rat lactating mammary gland.
1999
The Na(+)-dependent L-glutamate transporters GLAST (EAAT1) and GLT-1 (EAAT2), were expressed in rat lactating mammary gland, but EAAC1 (EAAT3) was not. GLT-1 expression in rat lactating mammary gland was constant in all the physiological situations studied; however, the GLAST expression is under tight regulation. Fasting for 24 h decreased the GLAST expression which returned to control values after refeeding. Weaning for 24 h produced a decrease in GLAST expression through a mechanism independent of prolactin deficiency. Resuckling for 6 h returned the expression of this transporter to control values. There is a correlation between the levels of GLAST (mRNA and protein) and the in vivo upta…
CyaC, a redox-regulated adenylate cyclase of Sinorhizobium meliloti with a quinone responsive diheme-B membrane anchor domain.
2019
The nucleotide cyclase CyaC of Sinorhizobium meliloti is a member of class III adenylate cyclases (AC), a diverse group present in all forms of life. CyaC is membrane-integral by a hexahelical membrane domain (6TM) with the basic topology of mammalian ACs. The 6TM domain of CyaC contains a tetra-histidine signature that is universally present in the membrane anchors of bacterial diheme-B succinate-quinone oxidoreductases. Heterologous expression of cyaC imparted activity for cAMP formation from ATP to Escherichia coli, whereas guanylate cyclase activity was not detectable. Detergent solubilized and purified CyaC was a diheme-B protein and carried a binuclear iron-sulfur cluster. Single poin…
Cationic amino acid transport across the blood-brain barrier is mediated exclusively by system y+.
2006
Cationic amino acid (CAA) transport is brought about by two families of proteins that are found in various tissues: Cat (CAA transporter), referred to as system y+, and Bat [broad-scope amino acid (AA) transporter], which comprises systems b0,+, B0,+, and y+L. CAA traverse the blood-brain barrier (BBB), but experiments done in vivo have only been able to examine the BBB from the luminal (blood-facing) side. In the present study, plasma membranes isolated from bovine brain microvessels were used to identify and characterize the CAA transporter(s) on both sides of the BBB. From these studies, it was concluded that system y+was the only transporter present, with a prevalence of activity on the…
Problematyka kształtowania zrównoważonych systemów transportowych peryferyjnych obszarów miast na przykładzie dzielnicy przemysłowej Metalchem w Opolu
2015
Zapewnienie efektywnego funkcjonowania systemów transportowych obszarów peryferyjnych w miastach bywa niejednokrotnie trudne, na co składa się wiele przyczyn. Celem artykułu jest przedstawienie wyników badań dotyczących poziomu zrównoważenia, w tym funkcjonalności, transportu w peryferyjnej dzielnicy przemysłowej Opola Metalchem, jak też ocena planów władz miasta co do zmian w systemie transportowym dzielnicy. Zdiagnozowane zostały główne elementy systemu transportowego oraz problemy związane z funkcjami, jakie na badanym obszarze powinien on pełnić. Następnie omówiono plany władz miasta dotyczące zmian w zagospodarowaniu dzielnicy, w tym przekształceń systemu transportowego. Ostatnia część…
Could Technology and Intelligent Transport Systems Help Improve Mobility in an Emerging Country? Challenges, Opportunities, Gaps and Other Evidence f…
2022
Apart from constituting a topic of high relevance for transport planners and policymakers, support technologies for traffic have the potential to bring significant benefits to mobility. In addition, there are groups of “high potential” users, such as young adults, who constitute an essential part of the current market. Notwithstanding, and especially in low and middle-income countries (LMICs), their knowledge and acceptance remain understudied. This study aimed to assess the appraisal of intelligent transport systems (ITS) and other technological developments applicable to mobility among Dominican young adults. Methods: In this study, we used the data gathered from 1414 Dominicans aged betw…
The Amino Acid Transporter JhI-21 Coevolves with Glutamate Receptors, Impacts NMJ Physiology, and Influences Locomotor Activity in Drosophila Larvae
2015
AbstractChanges in synaptic physiology underlie neuronal network plasticity and behavioral phenomena, which are adjusted during development. The Drosophila larval glutamatergic neuromuscular junction (NMJ) represents a powerful synaptic model to investigate factors impacting these processes. Amino acids such as glutamate have been shown to regulate Drosophila NMJ physiology by modulating the clustering of postsynaptic glutamate receptors and thereby regulating the strength of signal transmission from the motor neuron to the muscle cell. To identify amino acid transporters impacting glutmatergic signal transmission, we used Evolutionary Rate Covariation (ERC), a recently developed bioinforma…
Inhibition of iNOS activity by 1400W decreases glutamate release and ameliorates stroke outcome after experimental ischemia
2005
Background and purpose. It has been shown that the reversed operation of glutamate transporters when ATP levels fall accounts for most glutamate release induced by severe cerebral ischemia. Nitric oxide (NO) is formed after ischemia and causes ATP depletion. Our purpose is to test if NO release from inducible NO synthase (iNOS) after stroke may cause a delayed glutamate release due to ATP depletion that might underlie progression of the ischemic infarct. We have studied the effect of the highly selective inhibitor of iNOS activity 1400W on brain ATP levels, extracellular glutamate, and stroke outcome after transient focal cerebral ischemia in rats. Methods. To induce focal ischemia, the mid…
Activation of L-arginine transport by protein kinase C in rabbit, rat and mouse alveolar macrophages
1998
1 The role of protein kinase C in controlling L-arginine transport in alveolar macrophages was investigated. 2 L-[3H]Arginine uptake in rabbit alveolar macrophages declined by 80 % after 20 h in culture. 4β-Phorbol 12-myristate 13-acetate (PMA), but not 4α-phorbol 12-myristate 13-acetate (α-PMA), present during 20 h culture, enhanced L-[3H]arginine uptake more than 10-fold. Staurosporine and chelerythrine opposed this effect. 3 L-[3H]Arginine uptake was saturable and blockable by L-lysine. After PMA treatment Vmax was increased more than 5-fold and Km was reduced from 0.65 to 0.32 mM. 4 Time course experiments showed that PMA increased L-[3H]arginine uptake almost maximally within 2 h. This…
A chimera carrying the functional domain of the orphan protein SLC7A14 in the backbone of SLC7A2 mediates trans-stimulated arginine transport.
2012
In human skin fibroblasts, a lysosomal transport system specific for cationic amino acids has been described and named system c. We asked if SLC7A14 (solute carrier family 7 member A14), an orphan protein assigned to the SLC7 subfamily of cationic amino acid transporters (CATs) due to sequence homology, may represent system c. Fusion proteins between SLC7A14 and enhanced GFP localized to intracellular vesicles, co-staining with the lysosomal marker LysoTracker(®). To perform transport studies, we first tried to redirect SLC7A14 to the plasma membrane (by mutating putative lysosomal targeting motifs) but without success. We then created a chimera carrying the backbone of human (h) CAT-2 and …
The on-line isotope separation facility helios at the mainz reactor
1980
Abstract The on-line isotope separation facility HELIOS consisting of a helium-jet transport system coupled to a high transmission mass separator is described. The main characteristics of the system were determined from γ-ray measurements on neutron-rich nuclides. The transmission from the target to the skimmer is about 60%; the overall efficiency for typical fission product elements is 0.05–0.2% and the transit time for Cs is about 1.0 s.