A subtractive tomato (Lycopersicon esculentum) root cDNA library enriched in genes up-regulated by changes in plant mineral status was screened with labeled mRNA from roots of both nitrate-induced and mineral nutrient-deficient (-nitrogen [N], -phosphorus, -potassium [K], -sulfur, -magnesium, -calcium, -iron, -zinc, and -copper) tomato plants. A subset of cDNAs was selected from this library ba...

Silicon (Si) improves plant growth and development especially under stress conditions. Although Si alleviates suppression deficiency symptoms of several nutrient disorders, underlying regulatory processes have remained indefinite. Here, we analyzed the impact on nutritional, metabolic transcriptional responses in roots shoots barley subjected to potassium (K) deficiency. On long run, nutrition ...

Transcellular calcium transport is an essential activity in mineralized tissue formation, including dental hard tissues. In many organ systems, this activity is regulated by membrane-bound sodium/calcium (Na(+)/Ca(2+)) exchangers, which include the NCX and NCKX [sodium/calcium-potassium (Na(+)/Ca(2+)-K(+)) exchanger] proteins. During enamel maturation, when crystals expand in thickness, Ca(2+) ...

We describe a scalable artificial bilayer lipid membrane platform for rapid electrophysiological screening of ion channels and transporters. A passive pumping method is used to flow microliter volumes of ligand solution across a suspended bilayer within a microfluidic chip. Bilayers are stable at flow rates up to ∼0.5 μl/min. Phospholipid bilayers are formed across a photolithographically defin...

The excitatory neurotransmitter glutamate is removed from the synaptic cleft by several related sodium- and potassium-coupled transporters. They thereby restrict the neurotoxicity of this transmitter. Based on the accessibility of single cysteines to the large sulfhydryl reagent 3-N-maleimidyl(propionyl)biocytin, we have proposed a topological model for the astroglial glutamate transporter GLT-...

Developing seeds are net importers of organic and inorganic nutrients. Nutrients enter seeds through the maternal vascular system at relatively high concentrations in the phloem. They exit importing sieve elements via interconnecting plasmodesmata and, during subsequent symplasmic passage, are sequestered into labile storage pools (vacuoles; starch). Transporters function to retrieve nutrients ...

Hypokalemia causes a significant decrease in the tonicity of the renal medullary interstitium in association with reduced expression of sodium transporters in the distal tubule. We asked whether hypokalemia caused downregulation of the tonicity-responsive enhancer binding protein (TonEBP) transcriptional activator in the renal medulla due to the reduced tonicity. We found that the abundance of ...

The physiological significance of neuroglial interactions in the CNS has been emphasized in neurological conditions such as epilepsy and brain ischemia. The Kv2.1 voltage-gated potassium channel is unique in its ability to form large clusters in the plasma membrane of neuronal cell bodies. We have previously shown that brain ischemia causes rapid dephosphorylation of Kv2.1 subunits and resultan...

Excitatory amino acid transporters (EAATs) use sodium and potassium gradients to remove glutamate from the synapse and surrounding extracellular space, thereby sustaining efficient synaptic transmission and maintaining extracellular glutamate concentrations at subneurotoxic levels. In addition to sodium-driven glutamate uptake, EAATs also mediate a glutamate-activated chloride conductance via a...

The Brunner's glands of the proximal duodenum exert barrier functions through secretion of glycoproteins and antimicrobial peptides. However, ion transporter localization, function, and regulation in the glands are less clear. Mapping the subcellular distribution of transporters is an important step toward elucidating trafficking mechanisms of fluid transport in the gland. The present study exa...