The reabsorption of salt in the distal nephron is predominantly mediated via the thiazide-sensitive sodium chroride cotransporter, NCC (SLC12A3), and the chloride-bicarbonate exchanger pendrin (SLC26A4, PDS), with pendrin working in tandem with the epithelial sodium channel and NCC working by itself. Single deletion of NCC or pendrin in genetically engineered mouse models does not cause salt wa...

The sodium chloride cotransporter (NCC) is the primary target of thiazides diuretics, drugs used commonly for long-term hypertension therapy. Thiazides also completely reverse the signs of familial hyperkalemic hypertension (FHHt), suggesting that the primary defect in FHHt is increased NCC activity. To test whether increased NCC abundance alone is sufficient to generate the FHHt phenotype, we ...

Angiotensin II (AngII) hypertension increases distal tubule Na-Cl cotransporter (NCC) abundance and phosphorylation (NCCp), as well as epithelial Na(+) channel abundance and activating cleavage. Acutely raising plasma [K(+)] by infusion or ingestion provokes a rapid decrease in NCCp that drives a compensatory kaliuresis. The first aim tested whether acutely raising plasma [K(+)] with a single 3...

The uptake and distribution of Pi in plants requires multiple Pi transport systems that must function in concert to maintain homeostasis throughout growth and development. The Pi transporter PHT2;1 of Arabidopsis shares similarity with members of the Pi transporter family, which includes Na(+)/Pi symporters of fungal and animal origin and H(+)/Pi symporters of bacterial origin. Sequence compari...

A procedure is described for the preparation of basolateral membrane vesicles from the acinar cells of the sheep parotid gland. The ouabain-sensitive K(+)-activated phosphatase activity was enriched 30-fold over the tissue homogenate; 45% of this activity was recovered in the final membrane fraction. The presence of membranes from other organelles was negligible. Evidence is presented for the l...

We examined molecular and electrophysiological properties of the electroneutral sodium/bicarbonate cotransporter (NBCn1) that is present in rat hippocampal neurons. By PCR, a deletion variant (NBCn1-E) that lacks 123 amino acids in the cytoplasmic N-terminal domain was found in adult neurons. The previously characterized NBCn1-B, which does not have the deletion, was detected in embryonic neuro...

The GltS Na+/glutamate permease of Escherichia coli is the most extensively studied member of the ESS family of bacterial glutamate:Na+ symporters. This paper presents the membrane topology analysis of the GltS with translational alkaline phosphatase and beta-galactosidase gene fusions generated by TnphoA, nested deletions and targeted fusions. The topology model suggested by the translational ...

Electrically silent Na(+)-(K+)-Cl- transporter systems are present in a wide variety of cells and serve diverse physiological functions. In chloride secretory and absorbing epithelia, these cotransporters provide the chloride entry mechanism crucial for transcellular chloride transport. We have isolated cDNAs encoding the two major electroneutral sodium-chloride transporters present in the mamm...

GABA is the primary inhibitory neurotransmitter in the adult mammalian brain. However, in neonatal animals, activation of Cl(-)-permeable GABA receptors is excitatory and appears to depend on the expression of a Na(+)-K(+)-2Cl- cotransporter (NKCC) that elevates intracellular Cl- levels, leading to a depolarized Cl- equilibrium potential (ECl). The change from excitation to inhibition appears t...