A subgroup of aquaporins that transport WATER; GLYCEROL; and other small solutes across CELL MEMBRANES.
A class of porins that allow the passage of WATER and other small molecules across CELL MEMBRANES.
A trihydroxy sugar alcohol that is an intermediate in carbohydrate and lipid metabolism. It is used as a solvent, emollient, pharmaceutical agent, and sweetening agent.
Aquaporin 3 is an aquaglyceroporin that is expressed in the KIDNEY COLLECTING DUCTS and is constitutively localized at the basolateral MEMBRANE.
A ketotriose compound. Its addition to blood preservation solutions results in better maintenance of 2,3-diphosphoglycerate levels during storage. It is readily phosphorylated to dihydroxyacetone phosphate by triokinase in erythrocytes. In combination with naphthoquinones it acts as a sunscreening agent.
Aquaporin 1 forms a water-specific channel that is constitutively expressed at the PLASMA MEMBRANE of ERYTHROCYTES and KIDNEY TUBULES, PROXIMAL. It provides these cells with a high permeability to WATER. In humans polymorphisms of this protein result in the Colton blood group antigen.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
Aquaporin 5 is a water-specific channel protein that is expressed primarily in alveolar, tracheal, and upper bronchial EPITHELIUM. It plays an important role in maintaining water HOMEOSTASIS in the LUNGS and may also regulate release of SALIVA and TEARS in the SALIVARY GLANDS and the LACRIMAL GLAND.
Aquaporin 4 is the major water-selective channel in the CENTRAL NERVOUS SYSTEM of mammals.

Channel-dependent permeation of water and glycerol in mouse morulae. (1/34)

The cryosensitivity of mammalian embryos depends on the stage of development. Because permeability to water and cryoprotectants plays an important role in cryopreservation, it is plausible that the permeability is involved in the difference in the tolerance to cryopreservation among embryos at different developmental stages. In this study, we examined the permeability to water and glycerol of mouse oocytes and embryos, and tried to deduce the pathway for the movement of water and glycerol. The water permeability (L(P), microm min(-1) atm(-1)) of oocytes and four-cell embryos at 25 degrees C was low (0.63-0.70) and its Arrhenius activation energy (E(a), kcal/mol) was high (11.6-12.3), which implies that the water permeates through the plasma membrane by simple diffusion. On the other hand, the L(p) of morulae and blastocysts was quite high (3.6-4.5) and its E(a) was quite low (5.1-6.3), which implies that the water moves through water channels. Aquaporin inhibitors, phloretin and p-(chloromercuri) benzene-sulfonate, reduced the L(p) of morulae significantly but not that of oocytes. By immunocytochemical analysis, aquaporin 3, which transports not only water but also glycerol, was detected in the morulae but not in the oocytes. Accordingly, the glycerol permeability (P(GLY), x 10(-3) cm/min) of oocytes was also low (0.01) and its E(a) was remarkably high (41.6), whereas P(GLY) of morulae was quite high (4.63) and its E(a) was low (10.0). Aquaporin inhibitors reduced the P(GLY) of morulae significantly. In conclusion, water and glycerol appear to move across the plasma membrane mainly by simple diffusion in oocytes but by facilitated diffusion through water channel(s) including aquaporin 3 in morulae.  (+info)

Chlorella virus MT325 encodes water and potassium channels that interact synergistically. (2/34)

Fast and selective transport of water through cell membranes is facilitated by water channels. Water channels belonging to the major intrinsic proteins (MIPs) family have been found in all three domains of life, Archaea, Bacteria, and Eukarya. Here we show that Chlorella virus MT325 has a water channel gene, aqpv1, that forms a functional aquaglyceroporin in oocytes. aqpv1 is transcribed during infection together with MT325 kcv, a gene encoding a previously undescribed type of viral potassium channel. Coexpression of AQPV1 and MT325-Kcv in Xenopus oocytes synergistically increases water transport, suggesting a possible concerted action of the two channels in the infection cycle. The two channels operate by a thermodynamically coupled mechanism that simultaneously alters water conductance and driving force for water movement. Considering the universal role of osmosis, this mechanism is relevant to any cell coexpressing water and potassium channels and could have pathological as well as basic physiological relevance.  (+info)

Methylarsonous acid transport by aquaglyceroporins. (3/34)

Many mammals methylate trivalent inorganic arsenic in liver to species that are released into the bloodstream and excreted in urine and feces. This study addresses how methylated arsenicals pass through cell membranes. We have previously shown that aquaglyceroporin channels, including Escherichia coli GlpF, Saccharomyces cerevisiae Fps1p, AQP7, and AQP9 from rat and human, conduct trivalent inorganic arsenic [As(III)] as arsenic trioxide, the protonated form of arsenite. One of the initial products of As(III) methylation is methylarsonous acid [MAs(III)], which is considerably more toxic than inorganic As(III). In this study, we investigated the ability of GlpF, Fps1p, and AQP9 to facilitate movement of MAs(III) and found that rat aquaglyceroporin conducted MAs(III) at a higher rate than the yeast homologue. In addition, rat AQP9 facilitates MAs(III) at a higher rate than As(III). These results demonstrate that aquaglyceroporins differ both in selectivity for and in transport rates of trivalent arsenicals. In this study, the requirement of AQP9 residues Phe-64 and Arg-219 for MAs(III) movement was examined. A hydrophobic residue at position 64 is not required for MAs(III) transport, whereas an arginine at residue 219 may be required. This is similar to that found for As(III), suggesting that As(III) and MAs(III) use the same translocation pathway in AQP9. Identification of MAs(III) as an AQP9 substrate is an important step in understanding physiologic responses to arsenic in mammals, including humans.  (+info)

Enhanced expression of multidrug resistance-associated protein 2 and reduced expression of aquaglyceroporin 3 in an arsenic-resistant human cell line. (4/34)

Arsenic-resistant cells (R15), derived from a human lung adenocarcinoma cell line (CL3), were 10-fold more resistant to sodium arsenite (As(III)). Because R15 cells accumulated less arsenic than parental CL3 cells, this arsenic resistance may be due to higher efflux and/or lower uptake of As(III). We therefore compared expression of the multidrug resistance-associated proteins MRP1, MRP2, and MRP3 in these two cell lines. MRP2 expression was 5-fold higher in R15 cells than in CL3 cells, whereas MRP1 and MRP3 expression levels were similar. Furthermore, verapamil and cyclosporin A, inhibitors of multidrug resistance transporters, significantly reduced the efflux of arsenic from R15. Thus, increased arsenic extrusion by MRP2 may contribute to arsenic resistance in R15 cells. We also examined the expression of several aquaglyceroporins (AQPs), which mediate As(III) uptake by cells. Little AQP7 or AQP9 mRNA was detected by reverse transcription-PCR in either cell line, whereas AQP3 mRNA expression was 2-fold lower in R15 cells than in CL3 cells. When AQP3 expression in CL3 cells was knocked down by RNA interference, CL3 cells accumulated less arsenic and became more resistant to As(III). Conversely, overexpression of AQP3 in human embryonic kidney 293T cells increased arsenic accumulation, and the cells were more susceptible to As(III) than 293T cells transfected with vector alone. These results suggest that AQP3 is involved in As(III) accumulation. Taken together, our results suggest that enhanced expression of MRP2 and lower expression of AQP3 are responsible for lower arsenic accumulation in arsenic-resistant R15 cells.  (+info)

The structure, function and regulation of the nodulin 26-like intrinsic protein family of plant aquaglyceroporins. (5/34)

The nodulin 26-like intrinsic protein family is a group of highly conserved multifunctional major intrinsic proteins that are unique to plants, and which transport a variety of uncharged solutes ranging from water to ammonia to glycerol. Based on structure-function studies, the NIP family can be subdivided into two subgroups (I and II) based on the identity of the amino acids in the selectivity-determining filter (ar/R region) of the transport pore. Both subgroups appear to contain multifunctional transporters with low to no water permeability and the ability to flux multiple uncharged solutes of varying sizes depending upon the composition of the residues of the ar/R filter. NIPs are subject to posttranslational phosphorylation by calcium-dependent protein kinases. In the case of the family archetype, soybean nodulin 26, phosphorylation has been shown to stimulate its transport activity and to be regulated in response to developmental as well as environmental cues, including osmotic stresses. NIPs tend to be expressed at low levels in the plant compared to other MIPs, and several exhibit cell or tissue specific expression that is subject to spatial and temporal regulation during development.  (+info)

Sequence and annotation of the 314-kb MT325 and the 321-kb FR483 viruses that infect Chlorella Pbi. (6/34)

Viruses MT325 and FR483, members of the family Phycodnaviridae, genus Chlorovirus, infect the fresh water, unicellular, eukaryotic, chlorella-like green alga, Chlorella Pbi. The 314,335-bp genome of MT325 and the 321,240-bp genome of FR483 are the first viruses that infect Chlorella Pbi to have their genomes sequenced and annotated. Furthermore, these genomes are the two smallest chlorella virus genomes sequenced to date, MT325 has 331 putative protein-encoding and 10 tRNA-encoding genes and FR483 has 335 putative protein-encoding and 9 tRNA-encoding genes. The protein-encoding genes are almost evenly distributed on both strands, and intergenic space is minimal. Approximately 40% of the viral gene products resemble entries in public databases, including some that are the first of their kind to be detected in a virus. For example, these unique gene products include an aquaglyceroporin in MT325, a potassium ion transporter protein and an alkyl sulfatase in FR483, and a dTDP-glucose pyrophosphorylase in both viruses. Comparison of MT325 and FR483 protein-encoding genes with the prototype chlorella virus PBCV-1 indicates that approximately 82% of the genes are present in all three viruses.  (+info)

Aquaglyceroporin PbAQP during intraerythrocytic development of the malaria parasite Plasmodium berghei. (7/34)

The malaria parasite can use host plasma glycerol for lipid biosynthesis and membrane biogenesis during the asexual intraerythrocytic development. The molecular basis for glycerol uptake into the parasite is undefined. We hypothesize that the Plasmodium aquaglyceroporin provides the pathway for glycerol uptake into the malaria parasite. To test this hypothesis, we identified the orthologue of Plasmodium falciparum aquaglyceroporin (PfAQP) in the rodent malaria parasite, Plasmodium berghei (PbAQP), and examined the biological role of PbAQP by performing a targeted deletion of the PbAQP gene. PbAQP and PfAQP are 62% identical in sequence. In contrast to the canonical NPA (Asn-Pro-Ala) motifs in most aquaporins, the PbAQP has NLA (Asn-Leu-Ala) and NPS (Asn-Leu-Ser) in those positions. PbAQP expressed in Xenopus oocytes was permeable to water and glycerol, suggesting that PbAQP is an aquaglyceroporin. In P. berghei, PbAQP was localized to the parasite plasma membrane. The PbAQP-null parasites were viable; however, they were highly deficient in glycerol transport. In addition, they proliferated more slowly compared with the WT parasites, and mice infected with PbAQP-null parasites survived longer. Taken together, these findings suggest that PbAQP provides the pathway for the entry of glycerol into P. berghei and contributes to the growth of the parasite during the asexual intraerythrocytic stages of infection. In conclusion, we demonstrate here that PbAQP plays an important role in the blood-stage development of the rodent malaria parasite during infection in mice and could be added to the list of targets for the design of antimalarial drugs.  (+info)

An arsenate-activated glutaredoxin from the arsenic hyperaccumulator fern Pteris vittata L. regulates intracellular arsenite. (8/34)

To elucidate the mechanisms of arsenic resistance in the arsenic hyperaccumulator fern Pteris vittata L., a cDNA for a glutaredoxin (Grx) Pv5-6 was isolated from a frond expression cDNA library based on the ability of the cDNA to increase arsenic resistance in Escherichia coli. The deduced amino acid sequence of Pv5-6 showed high homology with an Arabidopsis chloroplastic Grx and contained two CXXS putative catalytic motifs. Purified recombinant Pv5-6 exhibited glutaredoxin activity that was increased 1.6-fold by 10 mm arsenate. Site-specific mutation of Cys(67) to Ala(67) resulted in the loss of both GRX activity and arsenic resistance. PvGrx5 was expressed in E. coli mutants in which the arsenic resistance genes of the ars operon were deleted (strain AW3110), a deletion of the gene for the ArsC arsenate reductase (strain WC3110), and a strain in which the ars operon was deleted and the gene for the GlpF aquaglyceroporin was disrupted (strain OSBR1). Expression of PvGrx5 increased arsenic tolerance in strains AW3110 and WC3110, but not in OSBR1, suggesting that PvGrx5 had a role in cellular arsenic resistance independent of the ars operon genes but dependent on GlpF. AW3110 cells expressing PvGrx5 had significantly lower levels of arsenite when compared with vector controls when cultured in medium containing 2.5 mm arsenate. Our results are consistent with PvGrx5 having a role in regulating intracellular arsenite levels, by either directly or indirectly modulating the aquaglyceroporin. To our knowledge, PvGrx5 is the first plant Grx implicated in arsenic metabolism.  (+info)

TY - JOUR. T1 - Conditional osmotic stress in yeast. T2 - a system to study transport through aquaglyceroporins and osmostress signaling. AU - Karlgren, Sara. AU - Pettersson, Nina. AU - Nordlander, Bodil. AU - Mathai, John C.. AU - Brodsky, Jeffrey L.. AU - Zeidel, Mark L.. AU - Bill, Roslyn M.. AU - Hohmann, Stefan. N1 - © 2005 The American Society for Biochemistry and Molecular Biology, Inc.. PY - 2005/2/25. Y1 - 2005/2/25. N2 - The accumulation and transport of solutes are hallmarks of osmoadaptation. In this study we have employed the inability of the Saccharomyces cerevisiae gpd1Δ gpd2Δ mutant both to produce glycerol and to adapt to high osmolarity to study solute transport through aquaglyceroporins and the control of osmostress-induced signaling. High levels of different polyols, including glycerol, inhibited growth of the gpd1Δ gpd2Δ mutant. This growth inhibition was suppressed by expression of the hyperactive allele Fps1-AΔ of the osmogated yeast aquaglyceroporin, Fps1. The ...
Arsenic is one of the most ubiquitous toxins and endangers the health of tens of millions of humans worldwide. It is a mainly a water-borne contaminant. Inorganic trivalent arsenic (AsIII) is one of the major species that exists environmentally. The transport of AsIII has been studied in microbes, plants and mammals. Members of the aquaglyceroporin family have been shown to actively conduct AsIII and its organic metabolite, monomethylarsenite (MAsIII). However, the transport of AsIII and MAsIII in in any fish species has not been characterized. In this study, five members of the aquaglyceroporin family from zebrafish (Danio rerio) were cloned, and their ability to transport water, glycerol, and trivalent arsenicals (AsIII and MAsIII) and antimonite (SbIII) was investigated. Genes for at least seven aquaglyceroporins have been annotated in the zebrafish genome project. Here, five genes which are close homologues to human AQP3, AQP9 and AQP10 were cloned from a zebrafish cDNA preparation. These genes were
We recently demonstrated that the aquaglyceroporins (AQGPs) could act as potent transporters for orthosilicic acid (H4SiO4). Although interesting, this finding raised the question of whether water and H4SiO4, the transportable form of Si, permeate AQGPs by interacting with the same region of the pore, especially in view of the difference in molecular radius between the two substrates. Here, our goal was to identify residues that endow the AQGPs with the ability to facilitate Si diffusion by examining the transport characteristics of mutants in which residues were interchanged between a water-permeable but Si-impermeable channel (aquaporin 1 [AQP1]) and a Si-permeable but water-impermeable channel (AQP10). Our results indicate that the composition of the arginine filter (XX/R), known to include three residues that play an important role in water transport, may also be involved in Si selectivity. Interchanging the identities of the nonarginine residues within this filter causes Si transport to ...
Aims/objectives: Glycerol cycling plays an essential regulatory role in metabolism in both health and disease. Aquaporins (AQPs) are a recently described family of water transporting membrane proteins, which contain a subset of members that also have the ability to transport glycerol across the cell membrane. This study sought to investigate the adipose tissue expression profile of AQPs in humans, and to assess the role of AQPs in adipocyte differentiation.. Methods: AQP expression was assessed in ex vivo human adipose tissue samples and isolated human adipocytes. Mouse 3T3 L1 and human SGBS cells were also used for expression and differentiation studies. SYBR Green real-time PCR and Western Blotting were used to detect mRNA and protein expression respectively.. Results: AQP 3 and 7 were expressed in omental adipose tissue at a significantly higher level than in corresponding subcutaneous adipose tissue samples. AQP 7 was the most abundantly expressed aquaporin in both depots. In differentiating ...
Maldonado, Manuel ; López-Acosta, María ; Beazley, L.; Kenchington, Ellen L. R.; Koutsouveli, V.; Riesgo, A. Science Advances 6(28): eaba9322 (2020) DIGITAL CSIC. The biological utilization of dissolved silicon (DSi) influences ocean ecology and biogeochemistry. In the deep sea, hexactinellid sponges are major DSi consumers that remain poorly understood. Their DSi consumption departs from the Michaelis-Menten kinetics of shallow-water demosponges and appears particularly maladapted to incorporating DSi from the modest concentrations typical of the modern ocean. Why did sponges not adapt to the shrinking DSi availability that followed diatom expansion some 100 to 65 million years ago? We propose that sponges incorporate DSi combining passive (aquaglyceroporins) and active (ArsB) transporters, while only active transporters (SITs) operate in diatoms and choanoflagellates. Evolution of greater silicon transport efficiency appears constrained by the additional role of aquaglyceroporins in ...
Copes gray treefrog, Hyla chrysoscelis,is a freeze-tolerant anuran which accumulates and distributes glycerol as a cryoprotectant before freezing. We hypothesize that HC-3, an aquaglyceroporin member of the MIP family of water pores, may play an important role in the process of freeze tolerance by mediating transmembrane passage of glycerol and water during cold-acclimation. The objectives of this study were two-fold: to examine HC-3 protein abundance and cellular localization in erythrocytes from cold- and warm-acclimated frogs and to develop and characterize an erythrocyte cell culture system for examining HC-3 gene regulation. Compared with warm-acclimated frogs, erythrocytes from cold-acclimated frogs had higher HC-3 protein expression and enhanced plasma membrane localization. Furthermore, erythrocytes from cold- and warm-acclimated frogs maintained in culture at 4 and 20°C exhibited time- and temperature-dependent regulation of HC-3 expression and an increase in the abundance of high molecular
Screening assays designed to probe ligand and drug-candidate regulation of membrane proteins responsible for ion-translocation across the cell membrane are wide spread, while efficient means to screen membrane-protein facilitated transport of uncharged solutes are sparse. We report on a microfluidic-based system to monitor transport of uncharged solutes across the membrane of multiple (,100) individually resolved surface-immobilized liposomes. This was accomplished by rapidly switching (,10 ms) the solution above dye-containing liposomes immobilized on the floor of a microfluidic channel. With liposomes encapsulating the pH-sensitive dye carboxyfluorescein (CF), internal changes in pH induced by transport of a weak acid (acetic acid) could be measured at time scales down to 25 ms. The applicability of the set up to study biological transport reactions was demonstrated by examining the osmotic water permeability of human aquaporin (AQP5) reconstituted in proteoliposomes. In this case, the rate of ...
Screening assays designed to probe ligand and drug-candidate regulation of membrane proteins responsible for ion-translocation across the cell membrane are wide spread, while efficient means to screen membrane-protein facilitated transport of uncharged solutes are sparse. We report on a microfluidic-based system to monitor transport of uncharged solutes across the membrane of multiple (|100) individually resolved surface-immobilized liposomes. This was accomplished by rapidly switching (|10 ms) the solution above dye-containing liposomes immobilized on the floor of a microfluidic channel. With liposomes encapsulating the pH-sensitive dye carboxyfluorescein (CF), internal changes in pH induced by transport of a weak acid (acetic acid) could be measured at time scales down to 25 ms. The applicability of the set up to study biological transport reactions was demonstrated by examining the osmotic water permeability of human aquaporin (AQP5) reconstituted in proteoliposomes. In this case, the rate of osmotic
Recent investigations revealed that epithelial TJs contain charge- and size-selective pores, which control the paracellular flux of charged and uncharged solutes. The paracellular flux occurs through two distinct pathways: one high-capacity pathway with size-restrictive pores and one low-capacity pathway that is size independent, at least for substances with radii of up to 7 Å (Van Itallie et al., 2008; Watson et al., 2001). The physical basis of the low-capacity pathway is not yet completely understood, whereas the high-capacity pathway is well described. It consists of small pores with radii of ~4 Å, and is responsible for the flux of small charged and uncharged solutes. Expression of claudin-2 affects only the high-capacity pathway, by inducing an increase in pore number and a change in charge selectivity (Van Itallie et al., 2008). In a recent attempt to model the claudin-2-induced channel (Yu et al., 2009), the pore diameter, calculated from permeability to organic cations and from the ...
Stahl, Katja; Rahmani, Soulmaz; Prydz, Agnete; Skauli, Nadia; MacAulay, Nanna; Mylonakou, Maria-Niki; Torp, Reidun; Skare, Øivind; Berg, Torill; Leergaard, Trygve Brauns; Paulsen, Ragnhild Elisabeth; Ottersen, Ole Petter & Amiry-Moghaddam, Mahmood (2018). Targeted deletion of the aquaglyceroporin AQP9 is protective in a mouse model of Parkinsons disease. PLOS ONE. ISSN 1932-6203. 13(3) . doi: 10.1371/journal.pone.0194896 Fulltekst i vitenarkiv. Vis sammendrag More than 90% of the cases of Parkinsons disease have unknown etiology. Gradual loss of dopaminergic neurons of substantia nigra is the main cause of morbidity in this disease. External factors such as environmental toxins are believed to play a role in the cell loss, although the cause of the selective vulnerability of dopaminergic neurons remains unknown. We have previously shown that aquaglyceroporin AQP9 is expressed in dopaminergic neurons and astrocytes of rodent brain. AQP9 is permeable to a broad spectrum of substrates including ...
Background: Aquaporins are integral membrane proteins that facilitate the transport of water and small solutes across cell membranes. These proteins are vital for maintaining water homeostasis in living organisms. In mammals, thirteen aquaporins (AQP0-12) have been characterized, but in lower vertebrates, such as fish, the diversity, structure and substrate specificity of these membrane channel proteins are largely unknown. Results: The screening and isolation of transcripts from the zebrafish (Danio rerio) genome revealed eighteen sequences structurally related to the four subfamilies of tetrapod aquaporins, i.e., aquaporins (AQP0, -1 and -4), water and glycerol transporters or aquaglyceroporins (Glps; AQP3 and AQP7-10), a water and urea transporter (AQP8), and two unorthodox aquaporins (AQP11 and -12). Phylogenetic analyses of nucleotide and deduced amino acid sequences demonstrated dual paralogy between teleost and human aquaporins. Three of the duplicated zebrafish isoforms have unlinked ...
Liposome and micelle electrokinetic chromatography (EKC) were used to determine retention factors (k) that are directly related to partition coefficients (K) and the phase ratio (φ) as: k = K*φ. Linear solvation energy relationship (LSER) models were used to elucidate the contributions of solute partitioning into liposomes. In addition, an LSER model for both MEKC and LEKC was used to determine partition coefficients for solutes without observed partition coefficients. The observed partition coefficients and those determined from LSER were then used to predict partition coefficients with the group contribution approach (GCA) and the fragmental constant approach (FCA) from solute structure. In the GCA, a relatively small number of key monosubstituted aromatic and aliphatic solutes are used to determine the substituent constants of functional groups. These substituent constants as well as the contributions from aromatic and aliphatic carbon plus hydrogen are used to predict partition ...
Structural data on AQPs, together with mutagenesis and molecular dynamics simulations, have indicated that single-file transport occurs through a narrow pore in each monomer, where water selectivity is conferred by electrostatic and steric factors (Hub et al., 2009; Khalali-Araghi et al., 2009). Glycerol-transporting AQPs, called aquaglyceroporins, have a less-constricted pore compared with that of water-selective AQPs (diameter of 3.4 Å compared with 2.8 Å, respectively), with relatively more hydrophobic residues lining the pore.. Many mammalian AQPs, including AQP1, AQP2, AQP4, AQP5 and AQP8, function primarily as bidirectional water-selective transporters. Cells expressing AQPs on their plasma membrane have an ~5- to 50-fold higher osmotic water permeability than membranes that do not (Verkman and Mitra, 2000). Water transport through single-file pores poses a biophysical limitation on the efficiency with which AQPs can transport water, so that AQPs must be present in the membrane at a high ...
Aquaglyceroporin PbAQP during intraerythrocytic development of the malaria parasite Plasmodium berghei. (2007 Feb 13, Proc Natl Acad Sci U S A) PubMed / full text ...
Apparatus and methods are provided for forming a gastrointestinal tissue fold by engaging tissue at a first tissue contact point, moving the first tissue contact point from a position initially distal to a second tissue contact point to a position proximal of the second contact point to form a tissue fold, and extending an anchor assembly through the tissue fold near the second tissue contact point.
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Arsenic is a toxic metalloid which is widely distributed in nature. It is normally present as arsenate under oxic conditions while arsenite is predominant under reducing condition. The major discharges of arsenic in the environment are mainly due to natural sources such as aquifers and anthropogenic sources. It is known that arsenite salts are more toxic than arsenate as it binds with vicinal thiols in pyruvate dehydrogenase while arsenate inhibits the oxidative phosphorylation process. The common mechanisms for arsenic detoxification are uptaken by phosphate transporters, aquaglyceroporins, and active extrusion system and reduced by arsenate reductases via dissimilatory reduction mechanism. Some species of autotrophic and heterotrophic microorganisms use arsenic oxyanions for their regeneration of energy. Certain species of microorganisms are able to use arsenate as their nutrient in respiratory process. Detoxification operons are a common form of arsenic resistance in microorganisms. Hence, the use of
We evaluated the effects of dihydroxyacetone (DHA) on Trypanosoma brucei bloodstream forms. DHA is considered an energy source for many different cell types. T. brucei takes up DHA readily due to the presence of aquaglyceroporins. However, the parasi
Aquaporin membrane protein, molecular model. Computer illustration showing the structure of a molecule of the human aquaporin 1 protein (blue, and white ribbon). Aquaporins are membrane proteins that form channels (centre) that help water molecules (red and white spheres) pass in and out of cells. Unlike ion channels, aquaporins help prevent ions and other dissolved substances carrying electrical charge from entering the cell, as they only allow lone water molecules or certain uncharged solutes to pass through. This helps maintain the electrochemical potential of the cell membrane. - Stock Image C035/5236
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C. elegans AQP-4 protein; contains similarity to Pfam domain PF00230 (Major intrinsic protein)contains similarity to Interpro domains IPR000425 (Major intrinsic protein), IPR012269 (Aquaporin ...
By the end of this section, you will be able to: Describe the general preparation, properties, and uses of the metalloids Describe the preparation, pr
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Aquaglyceroporins-aquaporin membrane channels (AQP) that conduct glycerol and other small neutral solutes in addition to water-play major roles in obesity. In adipocytes, aquaglyceroporins mediate glycerol uptake and release across the plasma membrane, which are two key steps for triacylglycerols (TAGs) synthesis (lipogenesis) and hydrolysis (lipolysis). The aim of this study was to assess both glycerol permeability and metabolism in undifferentiated 3T3-L1 cells (UDCs) as well as in untreated (CTL-DCs) versus lipopolysaccharide (LPS-DCs)-treated differentiated 3T3-L1 adipocytes. Glycerol release, TAGs content and whole membrane glycerol permeability were significantly increased in DCs as compared to UDCs. Moreover, in DCs, LPS treatment significantly increased TAGs content and decreased glycerol permeability. In addition, a significant reduction in whole membrane glycerol permeability was observed in LPS-DCs as compared to CTL-DCs. The relative contributions of AQP3, AQP7 and AQP9 (facilitated
Open peer review is a system where authors know who the reviewers are, and the reviewers know who the authors are. If the manuscript is accepted, the named reviewer reports are published alongside the article. Pre-publication versions of the article and author comments to reviewers are available by contacting [email protected] All previous versions of the manuscript and all author responses to the reviewers are also available.. You can find further information about the peer review system here.. ...
Aquaporin 3 (AQP3) is an aquaglyceroporin that transports water and glycerol and is expressed in the epidermis, among other epithelial tissues. We have recently shown that there is an association between this glycerol channel and phospholipase D2 (PLD2) in caveolin-rich membrane microdomains. While …
Dr Tim Downing, one of the papers first authors from NUI Galway and the Sanger Institute said: We discovered that many of the parasites that were resistant to antimonial drug treatment had just two additional DNA bases in the gene LdAQP1, which produces an aquaglyceroporin protein. This insertion produces a scrambled version of this protein that can no longer move small molecules - including antimonials - across its cell membrane. These strains of L. donovani are likely to be resistant because they cannot take in the drugs.. Dr James Cotton, senior author of the study from the Sanger Institute said: If you want to control visceral leishmaniasis, you need to understand what is going on at the geographic epicentre of the disease, and you need to be able to see changes at the level of individual DNA bases in the parasites genomes. Until now studies have been limited to looking at small regions of the parasites DNA or at what happens in the laboratory. To truly understand what is happening in ...
Glycerol-3-phosphate ABC transporter, permease protein UgpA (TC 3.A.1.1.3; K17321 glycerol transport system substrate-binding ...
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TY - JOUR. T1 - ATP microelectrode biosensor for stable long-term in vitro monitoring from gastrointestinal tissue. AU - Patel, Bhavik. AU - Rogers, M.. AU - Wieder, T.. AU - OHare, D.. AU - Boutelle, M.G.. PY - 2011/2/15. Y1 - 2011/2/15. KW - Adenosine tri-phosphate. KW - Serotonin. KW - Ileum. KW - Colon. KW - Hexokinase. KW - Biosensor. U2 - 10.1016/j.bios.2010.11.033. DO - 10.1016/j.bios.2010.11.033. M3 - Article. VL - 26. SP - 2890. EP - 2896. JO - Biosensors & Bioelectronics. JF - Biosensors & Bioelectronics. SN - 0956-5663. IS - 6. ER - ...
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TY - JOUR. T1 - Aquaporin water channels - From atomic structure to clinical medicine. AU - Agre, Peter. AU - King, Landon S.. AU - Yasui, Masato. AU - Guggino, Wm B.. AU - Ottersen, Ole Petter. AU - Fujiyoshi, Yoshinori. AU - Engel, Andreas. AU - Nielsen, Søren. PY - 2002/7/1. Y1 - 2002/7/1. N2 - The water permeability of biological membranes has been a longstanding problem in physiology, but the proteins responsible for this remained unknown until discovery of the aquaporin 1 (AQP1) water channel protein. AQP1 is selectively permeated by water driven by osmotic gradients. The atomic structure of human AQP1 has recently been defined. Each subunit of the tetramer contains an individual aqueous pore that permits single-file passage of water molecules but interrupts the hydrogen bonding needed for passage of protons. At least 10 mammalian aquaporins have been identified, and these are selectively permeated by water (aquaporins) or water plus glycerol (aquaglyceroporins). The sites of expression ...
metalloid: A chemical element with properties intermediate between those of typical metals and nonmetals. Usually considered under this classification are the chemical elements boron, silicon,...
TY - JOUR. T1 - Quantitative microultrasound characterization of gastrointestinal tissue for ultrasound capsule endoscopy. AU - Lay, Holly S.. AU - Cox, Benjamin. AU - Demore, Christine. AU - Spalding, Gabriel C.. AU - Cochran, Sandy. PY - 2016/4/21. Y1 - 2016/4/21. N2 - Gastrointestinal (GI) disease progression is often characterized by cellular and architectural changes within the mucosal and sub-mucosal layers. One relevant disorder, Barretts esophagus, is of particular interest as a recognized predictor of esophageal cancer. To enhance the clinical ability to detect cellular changes deeper in tissue and earlier, we are exploring quantitative microultrasound) techniques in healthy ex vivo porcine GI tissue for implementation in ultrasound capsule endoscopy. A single-element, piezocomposite mUS transducer operating at fc = 47.7 MHz was used to obtain pulse-echo images of ex vivo porcine gastroesophageal samples, which were bisected and mechanically scanned along the long GI axis. Selected ...
Key enzyme in the regulation of glycerol uptake and metabolism. The protein encoded by this gene belongs to the FGGY kinase family. This protein is a key enzyme in the regulation of glycerol uptake and metabolism. It catalyzes the phosphorylation of glycerol by ATP, yielding ADP and glycerol-3-phosphate. Mutations in this gene are associated with glycerol kinase deficiency (GKD). Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Mar 2011]
How can you earn the best score possible for MIPS in 2020? We break down all the 2020 MIPS requirements that youll need to complete in order to achieve MIPS reporting success next year.
Ralstonia eutropha H16 is a well-studied bacterium with respect to biosynthesis of polyhydroxyalkanoates (PHAs), which has attracted attentions as biodegradable bio-based plastics. However, this strain shows quite poor growth on glycerol of which bulk supply has been increasing as a major by-product of biodiesel industries. This study examined enhancement of glycerol assimilation ability of R. eutropha H16 by introduction of the genes of aquaglyceroporin (glpF) and glycerol kinase (glpK) from Escherichia coli. Although introduction of glpFK Ec into the strain H16 using a multi-copy vector was not successful, a recombinant strain possessing glpFK Ec within the chromosome showed much faster growth on glycerol than H16. Further analyses clarified that weak expression of glpK Ec alone allowed to establish efficient glycerol assimilation pathway, indicating that the poor growth of H16 on glycerol was caused by insufficient kination activity to glycerol, as well as this strain had a potential ability ...
In mammals, methylation occurs in the liver by methyltransferases, the products being the (CH3)2AsOH (dimethylarsinous acid) and (CH3)2As(O)OH (dimethylarsinic acid), which have the oxidation states As(III) and As(V), respectively.[2] Although the mechanism of methylation of arsenic in humans has not been elucidated, the source of methyl is methionine, which suggests a role of S-adenosyl methionine.[25] Exposure to toxic doses begin when the livers methylation capacity is exceeded or inhibited. There are two major forms of arsenic that can enter the body, arsenic (III) and arsenic (V).[26] Arsenic (III) enters the cells though aquaporins 7 and 9, which is a type of aquaglyceroporin.[26] Arsenic (V) compounds use phosphate transporters to enter cells.[26] The arsenic (V) can be converted to arsenic (III) by the enzyme purine nucleoside phosphorylase.[26] This is classified as a bioactivation step, as although arsenic (III) is more toxic, it is more readily methylated.[27]. There are two routes ...
Glycerol uptake and glycerol kinase activity were studied in primary cultures of rat hepatocytes in the presence of either 1 nM insulin, 1 nM glucagon, or 100 nM dexamethasone, alone or in combination in
Transmembrane glycerol transport is an ancient biophysical property that evolved in selected subfamilies of water channel (aquaporin) proteins. Here, we conducted broad level genome (,550) and transcriptome (,300) analyses ...
SWISS-MODEL Template Library (SMTL) entry for 1lda. CRYSTAL STRUCTURE OF THE E. COLI GLYCEROL FACILITATOR (GLPF) WITHOUT SUBSTRATE GLYCEROL
Staphylococcus aureus; strain: COL; locus tag: SACOL1317 (SACOL_RS06715); symbol: glpP; product: glycerol uptake operon antiterminator regulatory protein
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This study characterises the somatostatin binding site in human gastrointestinal cancer and mucosa in terms of cationic specificity and relative affinity for three somatostatin analogues. Competitive displacement assays were performed on plasma membranes from human gastric and colonic tissues using radiolabelled somatostatin-14 as ligand. Comparison was made with the somatostatin binding site in rat cerebral cortex. In gastrointestinal tissue, magnesium decreased and sodium increased specific binding. By contrast, in rat cerebral cortex, the converse cationic effect was seen. These changes resulted from alterations in receptor density, with no change in receptor affinity. Displacement studies were then performed with somatostatin-14 and somatostatin analogues RC-160, somatuline, and octreotide. RC-160 and somatuline displaced radiolabel from binding sites in gastric and colonic cancer and mucosa with 10-fold lower affinity than the native peptide. Octreotide did not displace radioligand in ...
This paper summarizes our studies on metal and metalloid uptake by the date palm, Phoenix dactylifera L., a tree of considerable importance in arid regions. The typical concentrations of 17 elements in the date palm are summarized and compared with existing data in the scientific literature. The role and toxicity of these elements are considered. Issues encountered by us during sample collection, pre-treatment and chemical analysis are described. Future studies are suggested.
Even before visiting the west coast of the United States, many of us have heard of Silicon Valley which is a little south of San Francisco. This is where the electronics/Computer industry boom occurred. Why is Silicon attached to the name? This element, besides being famous for creating glass centuries ago is the 20th…
(Phys.org) -Boron is the ambivert of atoms. Technically classified as a metalloid, boron can undergo organic reactions, forming covalent bonds like carbon, but it can also form ions resulting in metal-like bonds. Several ...
... are recognized as a subset of the aquaporin family of proteins which conduct water, glycerol and other small ... Aquaglyceroporins are found in many species including bacteria, plants and humans. Because of their ubiquitous nature they are ... They have been identified as a possible source of metalloid contamination in agriculture as aquaglyceroporins were have been ... Madeira, Ana; Moura, Teresa F.; Soveral, Graça (2015-02-01). "Aquaglyceroporins: implications in adipose biology and obesity". ...
The aquaglyceroporins are permeable to water, but also to other small uncharged molecules such as glycerol. The third subfamily ... Hub, Jochen S.; de Groot, Bert L. (2008-01-29). "Mechanism of selectivity in aquaporins and aquaglyceroporins". Proceedings of ... The MIP superfamily includes three subfamilies: aquaporins, aquaglyceroporins and S-aquaporins. The aquaporins (AQPs) are water ...
Some of them, known as aquaglyceroporins, also transport other small uncharged dissolved molecules including ammonia, CO2, ... function and regulation of the nodulin 26-like intrinsic protein family of plant aquaglyceroporins". Biochim. Biophys. Acta. ...
Aquaporins and aquaglyceroporins exist in all life forms including invertebrates, plants, microbes, archaea, and parasites ... Permeated by water plus glycerol, aquaglyceroporins confer glycerol uptake to the basal level of skin, glycerol release from ...
... aquaglyceroporins MeSH D12.776.157.530.400.500.040.249.500 - aquaporin 3 MeSH D12.776.157.530.400.500.040.249.750 - aquaporin 6 ...
... aquaglyceroporins MeSH D12.776.543.550.425.730.040.249.500 - aquaporin 3 MeSH D12.776.543.550.425.730.040.249.750 - aquaporin 6 ... aquaglyceroporins MeSH D12.776.543.585.400.730.040.249.500 - aquaporin 3 MeSH D12.776.543.585.400.730.040.249.750 - aquaporin 6 ...

No data available that match "aquaglyceroporins"


  • At least 10 mammalian aquaporins have been identified, and these are selectively permeated by water (aquaporins) or water plus glycerol (aquaglyceroporins). (elsevier.com)
  • Transmembrane glycerol transport is typically facilitated by aquaglyceroporins in Prokaryota and Eukaryota. (uib.no)
  • Transmembrane conductance of small uncharged solutes such as glycerol typically occurs through aquaglyceroporins (Glps), which are commonly encoded by multiple genes in metazoan organisms. (uib.no)
  • AQP3, AQP7, AQP9 and AQP10 transport water as well as glycerol and are also called Aquaglyceroporins. (alomone.com)
  • Aquaporins have been classified into two subfamilies: i) strict aquaporins that only allow the passage of water and ii) the less selective aquaglyceroporins that transport water and other neutral solutes, such as glycerol, CO2 or urea. (cienciavida.org)
  • In addition, MD simulation results suggest that AqpM combines characteristics of strict aquaporins, such as the narrow SF and channel radius, with those of aquaglyceroporins, such as a more hydrophobic and less polar SF. (cienciavida.org)
  • The goal is to attain a high resolution structure that will reveal what lies behind the differences in specificity between the aquaporins and aquaglyceroporins. (chalmers.se)
  • Detoxification of arsenic includes uptake of AsV in the form of phosphate by phosphate transporters, uptake of AsIII in the form of arsenite by aquaglyceroporins, reduction of AsV to AsIII by arsenate reductase, oxidation and methylation of AsIII by arsenate oxidase and methyltransferase respectively and finally extrusion or sequestration of AsIII. (walshmedicalmedia.com)
  • Recently, a locus encoding two closely related aquaglyceroporins, AQP2 and AQP3, was linked to MPXR in a high-throughput loss-of-function screen. (pasteur.fr)
  • The structures of several aquaglyceroporins have been resolved to atomic resolution showing two or more glycerols bound inside a channel and confirming a glycerol-facilitator's affinity for its substrate glycerol. (utexas.edu)
  • aquaglyceroporins (AQP3,-7 -9 and -10), additionally permeable to glycerol and for some isoforms urea [14], and superaquaporins (AQP11 and 12) located within cells [12]. (ox.ac.uk)
  • others transport water plus glycerol (aquaglyceroporins). (nih.gov)
  • Among the different types of aquaglyceroporins are important since they transport water and other solutes, such as glycerol and urea, playing a key role in maintaining skin hydration levels. (botanicalbody.ng)
  • A subset of aquaporins that transport both water and glycerol, the `aquaglyceroporins', regulate glycerol content material in epidermal, fat and other tissues, and are involved in pores and skin hydration, cell proliferation, carcinogenesis and extra fat rate of metabolism. (caspase-pathway.com)
  • Aquaporins and aquaglyceroporins are membrane channels that allow the permeation of water and certain other small solutes across the cell membrane, or in the case of AQP6, AQP11 and AQP12A, intracellular membranes, such as vesicles and the endoplasmic reticulum membrane [16]. (ox.ac.uk)
  • This gene encodes a member of a subset of aquaporins called the aquaglyceroporins. (nih.gov)
  • Insulin- and leptin-mediated control of aquaglyceroporins in human adipocytes and hepatocytes is mediated via the PI3K/Akt/mTOR signaling cascade. (dbcls.jp)