aquaporin channels in kidney

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Aquaporins in kidney Eight aquaporins, including aquaporin-1, aquaporin-2, aquaporin-3, aquaporin-4, aquaporin-5, aquaporin-6, aquaporin-7, and aquaporin-11, are expressed in different segments and various cells in the kidney to maintain normal urine concentration function 60). Aquaporin-2 (AQP2) is the vasopressin-regulated water-channel protein expressed at the connecting tubule and collecting duct, and plays a key role in urine concentration and body-water homeostasis through short-term and long-term Abstract. This protein was shown to function as a water channel when expressed in Xenopus oocytes or when reconstituted into synthetic membranes.

This protein was shown to function as a water channel when expressed in Xenopus oocytes or when reconstituted into synthetic membranes. AQP3 and AQP4 are basolateral water channels located in the kidney collecting duct and represent exit pathways for water reabsorbed via AQP2. Several additional aquaporins have been identified in kidney, including AQP6, which is expressed at lower abundance in the collecting duct intercalated cells. The aquaporin water channels. Several aquaporin (AQP )-type water channels are expressed in kidney: AQP1 in the proximal tubule, thin descending limb of Henle, and vasa recta; AQP2 -6 in the collecting duct; AQP7 in the proximal tubule; AQP8 in the proximal tubule and collecting duct; and AQP11 in the endoplasmic reticulum of proximal tubule cells. The most studied aquaporins are compared in the following table: In plants In plants water is taken up from the soil through the roots, where it passes from the cortex into the vascular tissues. Aquaporins (AQPs) are a newly recognized family of transmembrane proteins that function as molecular water channels. (1999) by T Ma, Verkman AS Venue: J Physiol: Add To MetaCart. Renal excretion of AQP2 has been studied in humans, dogs, rats and mice. We examined whether aquaporins (AQPs), a family of membrane channel proteins that facilitate water transport, help mediate fluid balance in the mouse cervix during parturition. There are thirteen known types of aquaporins in mammals, and six of these are located in the kidney, but the existence of many more is suspected. Aquaporin Water Channels in Mammalian Kidney Hypernatremia can occur with normal, increased or decreased total body sodium content. Aquaporin-1 (AQP1) is a water channel protein expressed highly in the kidney, as well as in erythrocytes, choroid plexus, ciliary body, alveolar microvessels, gall bladder, placenta, and various other epithelia and endothelia (13). AQP2 is localized in the apical membrane and in intracellular vesicles which are targeted to the apical plasma membranes when stimulated by ADH. Aquaporins (AQPs) are a family of highly selective transmembrane channels that mainly transport water across the cell and some facilitate low-molecular-weight solutes. This protein was shown to function as a water channel when expressed in Xenopus oocytes or when reconstituted into synthetic membranes. Aquaporin 2 (AQP2) is a vasopressin-regulated water channel of the renal collecting duct and is excreted into urine. Aquaporin-1 from human red blood cells was the first to be discovered and is probably the best studied. NOVEL INSIGHTS INTO THE EXPRESSION AND AQUAPORINS IN THE KIDNEY Tools. Vasopressin increases water permeability of kidney collecting duct by inducing translocation of aquaporin-CD water channels to plasma membrane. At least four aquaporins are expressed in the kidney where they mediate rapid water transport across water-permeable epithelia and play critical roles in urinary concentrating and diluting processes. Seven aquaporin water channels are expressed in human kidneys, and they have key roles in maintaining body water homeostasis. It is highly expressed in the human body primarily at the end-feet of astrocytes . Hydrophobicity plots of their amino acid sequences predict that the aquaporins have six membrane-spanning segments, as depicted in the model of aquaporin-1 to the right.

Aquaporins in the kidney: from molecules to medicine. The effect of chronic lithium therapy on the expression of the vasopressin-regulated water channel Aquaporin-2 (AQP2) in rat kidney was examined. This could explain the noneffective action of aquaporin-2 in the immature kidney, despite a normal protein channel expression and excretion. In human kidneys, nine aquaporins (AQPs), including AQP1-8 and AQP11, have been found and are differentially expressed along the renal tubules and collecting ducts with distinct and critical roles in the regulation of body water homeostasis and urine concentration. Aquaporins in the kidney The seven aquaporins expressed in the kidney are AQP1, AQP2, AQP3, AQP4, AQP6, AQP7 and AQP11 ( Table 1 ). The long-awaited discovery of the first water channel protein by Agre and his colleagues 1, 2 has indeed opened a new field in the research of membrane transport. Mutations in the gene encoding AQP1 cause mild nephrogenic diabetes insipidus, but mutations in the gene encoding AQP2 are much more severe. Nowadays, the pathophysiologic functions of aquaporin-s in renal-specific cell types and liquid homeostasis have been deeply studied to provide the therapeutic targets. The data showed that aquaporin-s might be an ideal biomarker for renal diseases 79). Request PDF | On Jan 1, 2008, Sren Nielsen and others published Aquaporin Water Channels in Mammalian Kidney | Find, read and cite all the research you need on ResearchGate

A lot of data have increased understanding of the functions and m Aquaporins in kidney pathophysiology The aquaporin family of water channels in kidney.

by Peter Agre - Proceedings of the American Thoracic Society, , 2006 Abstract - Cited by 81 (2 self) - Add to MetaCart Of the thirteen known murine AQPs, AQP0-2, 6, 7, 9, 11 and 12 were absent or at the limits of detection. [ PMC free article] [ PubMed] [ Google Scholar] The study of the mechanisms involved in the regulation of collecting duct water permeability, in particular, has advanced very rapidly since the identification and characterization of aquaporin-2 (AQP2) in Physiol Rev by Sren Nielsen, Jrgen Frkir, David Marples, Tae-hwan Kwon, Peter Agre, Mark, A. Knepper " III.

Sorted by Branchial expression of an aquaporin 3 (AQP-3) homologue is downregulated in the European eel Anguilla anguilla following seawater acclimation In healthy individuals and in normal conditions, the plasma concentration of sodium ranges between 136 and 143 mEq/l of plasma, despite large individual variations in the intake of salt and water. The aquaporin family of water channels in kidney. These particles were believed to contain water channels. AQP2 is expressed only in the principal cells of renal collecting duct where it is the predominant vasopressin (ADH, antidiuretic hormone) regulated water channel. Aquaporin Water Channels in Kidney PETER AGRE Departments of Biological Chemistry and Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland. Intended for healthcare professionals Proc Natl Acad Sci U S A.

185 Baum and colleagues 189 found expression of aquaporin-2 (apical membrane) and aquaporin-3 (basolateral membrane) in rat epithelial cells derived from ureteric bud and collecting ducts. The discovery of aquaporin-1 (AQP1) by Agre and colleagues (Preston et al. Aquaporin-4 is the most common aquaporin in the brain, spinal cord, and optic nerve. Four additional aquaporins (AQP7, -8, -9, and -10) Researchers Phylogenetic analysis was used to dene type sequences to avoid extreme over-representation of some subfamilies, and as a measure of the quality of multiple sequence alignment. AQP2 is the vasopressin-regulated water channel in the collecting duct. ABSTRACT Water permeation and electrostatic interactions between water and channel are investigated in the Escherichia coli glycerol uptake facilitator GlpF, a member of the aquaporin water channel family, by molecular dynamics simulations. important role in kidney development and function (56). The longstanding puzzle of membrane water permeability was advanced by the discovery of channel-forming integral protein (CHIP). In the kidney, at least seven aquaporins are expressed at distinct sites. AQP1 is extremely abundant in the proximal tubule and descending thin limb and is essential for urinary concentration. AQP2 is exclusively expressed in the principal cells of the connecting tubule and collecting duct and is the predominant vasopressin-regulated water channel. As a first year medical student, I attended nearly 200 lectures, but I have clear recollections of only two. Several aquaporin-type water channels are expressed in mammalian kidney and lung: AQP1 in lung microvessels and kidney proximal tubule, thin descending limb of Henle, and vasa recta; AQP2 in apical membrane of collecting duct epithelium; AQP3 and AQP4 in basolateral membranes of airway and collectin This unique protein that was selectively permeable to water was named aquaporin (AQP) 3, and the ensuing discovery of many homologous proteins soon clarified that there is an AQP family.. At least four aquaporins are expressed in the kidney where they mediate rapid water transport across water-permeable epithelia and play critical roles in urinary concentrating and diluting processes. Impairment of their function can result in nephrogenic diabetes insipidus and other water-balance disorders. The aquaporin family of water channels in kidney Abstract The longstanding puzzle of membrane water permeability was advanced by the discovery of channel-forming integral protein (CHIP). The longstanding puzzle of membrane water permeability was advanced by the discovery of channel-forming integral protein (CHIP). Aquaporin water channels in gastrointestinal physiology. Skip to main content. The kidney is the central organ involved in maintaining water and sodium balance.

On the first day that autumn, Albert Lehninger canceled his planned lecture and Renal aquaporins. Aquaporins are "the plumbing system for cells". Water moves through cells in an organized way, most rapidly in tissues that have aquaporin water channels. For many years, scientists assumed that water leaked through the cell membrane, and some water does. However, this did not explain how water could move so quickly through some cells. AQP4 is expressed in brain, and is involved in both the pathogenesis and the recovery from brain edema. The kidney is the central organ involved in maintaining water and sodium balance. Site-directed mutagenesis and Aquaporins (AQPs) are a newly recognized family of transmembrane proteins that function as molecular water channels. Membranes were prepared from inner medulla of one kidney from each rat, while the contralateral one was fixed for immunofluorescence and immunoelectronmicroscopy. are basolateral water channels located in the kidney col-lecting duct and represent exit pathways for water reab-sorbed via AQP2.

1995 Feb 14;92(4):10131017. The discovery of the aquaporin family of water channels has greatly improved our understanding of how water crosses epithelial cells, particularly in the kidney. CiteSeerX - Scientific documents that cite the following paper: Aquaporin-6: An intracellular vesicle water channel protein in renal epithelia.

Targeting the collecting duct water channel aquaporin 2 (AQP2) to the plasma membrane is essential for the maintenance of mammalian water homeostasis. Aquaporin-2 is critical in regulating urine concentrating ability. Al-though it has been proposed that autophagy may be involved in the development of polycystic kidney disease (PKD) in AQP11-null mice (83), the physiological role of AQP11 re-mains largely uncharacterized. In human kidneys, nine aquaporins (AQPs), including AQP18 and AQP11, have been found and are differentially expressed along the renal tubules and collecting ducts with distinct and critical roles in the regulation of body water homeostasis and urine concentration. The large number of sequences available for the aquaporin family represents a valuable source of information to incorporate into three-dimensional structure determination. : Several aquaporin-type water channels are expressed in mammalian kidney and lung: AQP1 in lung microvessels and kidney proximal tubule, thin descending limb of Henle, and vasa recta; AQP2 in apical membrane of collecting duct epithelium; AQP3 and AQP4 in basolateral membranes of airway and collecting duct epithelium; and AQP5 in alveolar epithelium. Several additional aquaporins have been identied in kidney, including AQP6, which is expressed at lower abundance in the collecting duct intercalated cells.

aquaporin channels in kidney