Expression cloning in Xenopus laevisoocytes was used to isolate an organic anion transport protein from rat kidney. A cDNA library constructed size-fractionated poly(A)+ RNA and screened for probenecid-sensitive of p-aminohippurate (PAH). 2,227-base pair clone containing a 1,656-base open reading frame coding peptide 551 amino acids long isolated named ROAT1. ROAT1-mediated 50 μm [3H]PAH independent imposed changes membrane potential. Transport significantly inhibited at 4 °C, or upon...

Abstract Much of iron and manganese metabolism occurs in mitochondria. Uptake redox-active must be tightly controlled, but little is known about how metal ions enter Recently, we established that the divalent transporter 1 (DMT1) present outer mitochondrial membrane (OMM). Therefore asked if it mediates Fe 2+ Mn influx. Mitochondria were isolated from HEK293 cells permanently transfected with inducible rat DMT1 isoform A/+IRE (HEK293-rDMT1). -induced quenching dye PhenGreen™SK (PGSK)...

The cDNA coding for a renal p ‐aminohippurate (PAH) transporter from winter flounder ( Pseudopleuronectes americanus ), designated fROAT, was cloned by functional expression in Xenopus laevis oocytes. fROAT is approximately 2.8 kbp length and encodes protein of 562 amino acids, related to the rat organic anion ROAT1/OAT1 cation transporters OCT1 OCT2. In oocytes, mediated probenecid‐sensitive PAH uptake, with K m about 20 μM, inhibited external glutarate (GA) (1 mM). characteristics suggest...

Background/Aims: Renal secretion of organic anions is critically dependent on their basolateral uptake against the electrochemical gradient. Due to localization, two transporters are likely involved, namely OAT1 and OAT3. While as an exchanger clearly operates in secretory direction, OAT3 its previously supposed mode a uniporter should move anionic substrates from cell blood. It would thus dissipate gradients established by common OAT1/OAT3 substrates. In present study we therefore...

Chronic cadmium (Cd²⁺) exposure results in renal proximal tubular cell damage. Delivery of Cd²⁺ to the kidney occurs mainly as complexes with metallothionein-1 (molecular mass ∼ 7 kDa), freely filtered at glomerulus. For gain access tubule cells, these are thought be internalized via receptors for small protein ligands, such megalin and cubilin, followed by release from endosomal/lysosomal compartments. To investigate role cadmium-metallothionein-1 reabsorption,...

In the kidney, bulk reabsorption of filtered proteins occurs in proximal tubule via receptor-mediated endocytosis (RME) through multiligand receptor complex megalin-cubilin. Other mechanisms and nephron sites for RME are unclear. Recently, secreted protein 24p3 (lipocalin-2, neutrophil gelatinase-associated lipocalin (NGAL)), which is expressed distal nephron, has been identified as a sensitive biomarker kidney damage. A high-affinity (24p3R) that involved endocytotic iron delivery also...

Neural stem cells (NSCs) are potential sources for cell therapy of neurodegenerative diseases and drug screening. Despite their benefits, ethical practical considerations limit the application NSCs derived from human embryonic (ES) or adult brain tissue. Thus, alternative required to satisfy criteria ready accessibility, rapid expansion in chemically defined media reliable induction a neuronal fate. We isolated somatic periodontium that were collected during minimally invasive periodontal...

Research Articles| November 13 2008 Cloning of a Human Renal p–Aminohippurate Transporter, hROAT1 Subject Area: Cardiovascular System , Nephrology Glen Reid; Reid aZentrum Physiologie und Pathophysiologie, Göttingen, Search for other works by this author on: This Site PubMed Google Scholar Natascha A. Wolff; Wolff Frank M. Dautzenberg; Dautzenberg bMax–Planck–Institut für Experimentelle Medizin, Deutschland Gerhard Burckhardt Kidney Blood Press Res (1998) 21 (2-4): 233–237....

The H + -coupled polyligand transport protein divalent metal transporter 1 (DMT1) plays a key role in mammalian iron homeostasis. It has widespread pattern of expression including tissues associated with acquisition and storage. Interestingly, it is also highly expressed the kidney, yet its function this tissue unknown. aim study was to determine cellular location DMT1 proximal tubule cells as first step determining kidney. To do we performed RT-PCR immunostaining experiments using rat...

Ferroportin 1 (FPN1) is an iron export protein expressed in liver and duodenum, as well reticuloendothelial macrophages. Previously, we have shown that divalent metal transporter (DMT1) late endosomes lysosomes of the kidney proximal tubule (PT), nephron segment responsible for majority solute reabsorption. We suggested following receptor mediated endocytosis transferrin filtered by glomerulus, DMT1 exports liberated from into cytosol. FPN1 also yet its role remains obscure. As a first step...

In mammalian cells, mitochondria receive most incoming iron, yet no entry pathway for iron at the outer mitochondrial membrane (OMM) has been characterized. Our results show that divalent metal transporter 1 (DMT1) occurs in OMM. Immunoblots detected DMT1 from a pneumocyte cell model their Using split-ubiquitin yeast 2-hybrid system, we found cytochrome c oxidase subunit II (COXII) and translocase of OMM 6-kDa (Tom6) homologue interact with DMT1. COXII coimmunoprecipitates There are 4...

ABSTRACT. Organic anion transport in intact renal proximal tubule cells animal model systems is downregulated by treatments that activate protein kinase C (PKC). How this downregulation achieved not yet known. Stimulation of PKC with sn-1,2-dioctanoylglycerol resulted strong inhibition p-aminohippurate mediated the cloned human organic transporter 1 (hOAT1) expressed Xenopus oocytes and HEK293 cells, as well hOAT1 internalization both expression systems. The sn-1,2-dioctanoylglycerol-induced...

Chronic exposure to Cd 2+ causes renal proximal tubular (PT) damage. reaches the PT mainly as cadmium-metallothionein 1 (CdMT-1) complexes that are filtered at glomerulus and then internalized in part via endocytosis mediated by megalin cubulin. Subsequently, is thought be released cytosol activate cell death pathways. The proton-coupled divalent metal transporter DMT1 also transports expressed exclusively endosomes/lysosomes rat cells. Using vector-based RNA interference with short-hairpin...

The class 1 carcinogen cadmium (Cd2+) disrupts the E-cadherin/beta-catenin complex of epithelial adherens junctions (AJs) and causes renal cancer. Deregulation E-cadherin adhesion changes in Wnt/beta-catenin signaling are known to contribute carcinogenesis.We investigated Wnt after Cd2+-induced disruption sub-confluent cultured kidney proximal tubule cells (PTC). Cd2+ (25 microM, 3-9 h) caused nuclear translocation beta-catenin triggered a response measured by TOPflash reporter assays....

Polyspecific organic cation transporter Oct2 from rat (gene Slc22A2) has been previously shown to transport Cs+. Here we report that human OCT2 (hOCT2) is able Cd2+ showing substrate saturation with a Michaelis–Menten constant (Km) of 54 ± 5.8 μM. Uptake by hOCT2 was inhibited typical ligands (unlabeled substrates and inhibitors), the rate uptake decreased point mutation in binding domain hOCT2. Incubation overexpressing embryonic kidney 293 cells (HEK-hOCT2-C) or renal proximal tubule...

The neutrophil gelatinase-associated lipocalin (NGAL, also known as LCN2) and its cellular receptor (LCN2-R, SLC22A17) are involved in many physiological pathological processes such cell differentiation, apoptosis, inflammation. These pleiotropic functions mainly rely on NGAL's siderophore-mediated iron transport properties. However, the molecular determinants underlying interaction between NGAL remain largely unknown. Here, using solution-state biomolecular NMR conjunction with other...

The divalent metal transporter (DMT1) is well known for its roles in duodenal iron absorption across the apical enterocyte membrane, efflux from endosome during transferrin-dependent cellular acquisition, as uptake of non-transferrin bound many cells. Recently, using multiple approaches, we have obtained evidence that mitochondrial outer membrane another subcellular locale DMT1 expression. While vital importance energy metabolism, delivery likely to be tightly controlled due iron's damaging...

We used equilibrium dialysis to measure the osmotic pressure of chondroitin sulphate (CS) solutions as a function their concentration and fixed charge density (FCD) ionic strength composition solution. Osmotic varied nonlinearly with in 0.15 M NaCl at FCDs typical uncompressed cartilage (approximately 0.4 mmol/g extrafibrillar H2O) was ~3 atmospheres. fell by 60% solution increased up about 1 M, but remained relatively constant higher strengths. The ratio Ca2+ Na+ medium minor determinant...