Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
J Biol Chem
2012 Mar 02;28710:7487-94. doi: 10.1074/jbc.M111.329102.
Show Gene links
Show Anatomy links
Functional characterization of a novel aquaporin from Dictyostelium discoideum amoebae implies a unique gating mechanism.
von Bülow J
,
Müller-Lucks A
,
Kai L
,
Bernhard F
,
Beitz E
.
???displayArticle.abstract???
The social amoeba Dictyostelium discoideum is a widely used model organism for studying basic functions of protozoan and metazoan cells, such as osmoregulation and cell motility. There is evidence from other species that cellular water channels, aquaporins (AQP), are central to both processes. Yet, data on D. discoideum AQPs is almost absent. Despite cloning of two putative D. discoideum AQPs, WacA, and AqpA, water permeability has not been shown. Further, WacA and AqpA are expressed at the late multicellular stage and in spores but not in amoebae. We cloned a novel AQP, AqpB, from amoeboidal D. discoideum cells. Wild-type AqpB was impermeable to water, glycerol, and urea when expressed in Xenopus laevis oocytes. Neither stepwise truncation of the N terminus nor selected point mutations activated the water channel. However, mutational truncation by 12 amino acids of an extraordinary long intracellular loop induced water permeability of AqpB, hinting at a novel gating mechanism. This AqpB mutant was inhibited by mercuric chloride, confirming the presence of a cysteine residue in the selectivity filter as predicted by our structure model. We detected AqpB by Western blot analysis in a glycosylated and a non-glycosylated form throughout all developmental stages. When expressed in D. discoideum amoebae, AqpB-GFP fusion constructs localized to vacuolar structures, to the plasma membrane, and to lamellipodia-like membrane protrusions. We conclude that the localization pattern in conjunction with channel gating may be indicative of AqpB functions in osmoregulation as well as cell motility of D. discoideum.
Annesley,
Dictyostelium discoideum--a model for many reasons.
2009, Pubmed
Annesley,
Dictyostelium discoideum--a model for many reasons.
2009,
Pubmed
Bapteste,
The analysis of 100 genes supports the grouping of three highly divergent amoebae: Dictyostelium, Entamoeba, and Mastigamoeba.
2002,
Pubmed
Beitz,
Aquaporins from pathogenic protozoan parasites: structure, function and potential for chemotherapy.
2005,
Pubmed
Beitz,
T(E)Xtopo: shaded membrane protein topology plots in LAT(E)X2epsilon.
2000,
Pubmed
Beitz,
Molecular dissection of water and glycerol permeability of the aquaglyceroporin from Plasmodium falciparum by mutational analysis.
2004,
Pubmed
Beitz,
Point mutations in the aromatic/arginine region in aquaporin 1 allow passage of urea, glycerol, ammonia, and protons.
2006,
Pubmed
,
Xenbase
Echevarria,
Cloning and expression of AQP3, a water channel from the medullary collecting duct of rat kidney.
1994,
Pubmed
,
Xenbase
Eichinger,
The genome of the social amoeba Dictyostelium discoideum.
2005,
Pubmed
Fischer,
Crystal structure of a yeast aquaporin at 1.15 angstrom reveals a novel gating mechanism.
2009,
Pubmed
Flick,
The wacA gene of Dictyostelium discoideum is a developmentally regulated member of the MIP family.
1997,
Pubmed
Fu,
Structure of a glycerol-conducting channel and the basis for its selectivity.
2000,
Pubmed
GRIMBLEBY,
Binding of trichloroacetic acid by protein.
1961,
Pubmed
Gupta,
Scanning the available Dictyostelium discoideum proteome for O-linked GlcNAc glycosylation sites using neural networks.
1999,
Pubmed
Habermann,
The BAR-domain family of proteins: a case of bending and binding?
2004,
Pubmed
Hansen,
A single, bi-functional aquaglyceroporin in blood-stage Plasmodium falciparum malaria parasites.
2002,
Pubmed
,
Xenbase
Haynes,
Phosphoglycosylation: a new structural class of glycosylation?
1998,
Pubmed
Holm,
NH3 and NH4+ permeability in aquaporin-expressing Xenopus oocytes.
2005,
Pubmed
,
Xenbase
Huang,
Functional analysis of the aquaporin gene family in Caenorhabditis elegans.
2007,
Pubmed
,
Xenbase
Kai,
Preparative scale production of functional mouse aquaporin 4 using different cell-free expression modes.
2010,
Pubmed
Klammt,
High level cell-free expression and specific labeling of integral membrane proteins.
2004,
Pubmed
Klammt,
Evaluation of detergents for the soluble expression of alpha-helical and beta-barrel-type integral membrane proteins by a preparative scale individual cell-free expression system.
2005,
Pubmed
Langridge,
Blebbing of Dictyostelium cells in response to chemoattractant.
2006,
Pubmed
Liu,
Urea transport by nitrogen-regulated tonoplast intrinsic proteins in Arabidopsis.
2003,
Pubmed
,
Xenbase
Luyten,
Fps1, a yeast member of the MIP family of channel proteins, is a facilitator for glycerol uptake and efflux and is inactive under osmotic stress.
1995,
Pubmed
Marchesini,
Acidocalcisomes are functionally linked to the contractile vacuole of Dictyostelium discoideum.
2002,
Pubmed
Mitra,
Loss of a member of the aquaporin gene family, aqpA affects spore dormancy in Dictyostelium.
2000,
Pubmed
Montalvetti,
A functional aquaporin co-localizes with the vacuolar proton pyrophosphatase to acidocalcisomes and the contractile vacuole complex of Trypanosoma cruzi.
2004,
Pubmed
,
Xenbase
Nishihara,
Presence of aquaporin and V-ATPase on the contractile vacuole of Amoeba proteus.
2008,
Pubmed
,
Xenbase
Pavlovic-Djuranovic,
Dihydroxyacetone and methylglyoxal as permeants of the Plasmodium aquaglyceroporin inhibit parasite proliferation.
2006,
Pubmed
,
Xenbase
Preston,
Mutations in aquaporin-1 in phenotypically normal humans without functional CHIP water channels.
1994,
Pubmed
,
Xenbase
RAPER,
Stalk formation in Dictyostelium.
1950,
Pubmed
Saadoun,
Impairment of angiogenesis and cell migration by targeted aquaporin-1 gene disruption.
2005,
Pubmed
Schneider,
Membrane protein expression in cell-free systems.
2010,
Pubmed
Sui,
Structural basis of water-specific transport through the AQP1 water channel.
,
Pubmed
Tamás,
A short regulatory domain restricts glycerol transport through yeast Fps1p.
2003,
Pubmed
Thrane,
Critical role of aquaporin-4 (AQP4) in astrocytic Ca2+ signaling events elicited by cerebral edema.
2011,
Pubmed
Törnroth-Horsefield,
Structural mechanism of plant aquaporin gating.
2006,
Pubmed
Uzcategui,
Cloning, heterologous expression, and characterization of three aquaglyceroporins from Trypanosoma brucei.
2004,
Pubmed
,
Xenbase
Watts,
Growth of myxameobae of the cellular slime mould Dictyostelium discoideum in axenic culture.
1970,
Pubmed
Wu,
Concerted action of two cation filters in the aquaporin water channel.
2009,
Pubmed
,
Xenbase
Wu,
Novel channel enzyme fusion proteins confer arsenate resistance.
2010,
Pubmed
Yasui,
Rapid gating and anion permeability of an intracellular aquaporin.
1999,
Pubmed
,
Xenbase
Zeidel,
Ultrastructure, pharmacologic inhibition, and transport selectivity of aquaporin channel-forming integral protein in proteoliposomes.
1994,
Pubmed
Zeuthen,
Ammonia permeability of the aquaglyceroporins from Plasmodium falciparum, Toxoplasma gondii and Trypansoma brucei.
2006,
Pubmed
,
Xenbase
Zhang,
Expression of aquaporin 5 increases proliferation and metastasis potential of lung cancer.
2010,
Pubmed
de Groot,
Water permeation across biological membranes: mechanism and dynamics of aquaporin-1 and GlpF.
2001,
Pubmed