Discovery of the Aquaporins and Development of the Field

Carbrey, Jennifer M.; Agre, Peter

doi:10.1007/978-3-540-79885-9_1

Cited by 191 publications

(147 citation statements)

References 159 publications

(150 reference statements)

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“…Aquaporin water channels (AQPs) play an important role in the physiological and pathophysiological processes of fluid transduction in diverse mammalian organs (1)(2)(3). AQPs are also involved in tissue injury and repair, tumor cell growth and angiogenesis by regulation of cell migration, proliferation, and apoptosis (4)(5)(6).…”

Section: Introductionmentioning

confidence: 99%

NPA motifs play a key role in plasma membrane targeting of aquaporin‐4

Guan

et al. 2010

IUBMB Life

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SummaryThe two highly conserved NPA motifs (asparagine-prolinealanine, NPA) are the most important structural domains that play a crucial role in water-selective permeation in aquaporin water channels. However, the functions of NPA motifs in aquaporin (AQP) biogenesis remain largely unknown. Few AQP members with variations in NPA motifs such as AQP11 and AQP12 do not express in the plasma membrane, suggesting an important role of NPA motifs in AQP plasma membrane targeting. In this study, we examined the role of the two NPA motifs in AQP4 plasma membrane targeting by mutagenesis. We constructed a series of AQP4 mutants with NPA deletions or single amino acid substitutions in AQP4-M1 and AQP4-M23 isoforms and analyzed their expression patterns in transiently transfected FRT and COS-7 cells. Western blot analysis showed similar protein bands of all the AQP4 mutants and the wild-type AQP4. AQP4 immunofluorescence indicated that deletion of one or both NPA motifs resulted in defective plasma membrane targeting, with apparent retention in endoplasmic reticulum (ER). The A99T mutant mimicking AQP12 results in ER retention, whereas the A99C mutant mimicking AQP11 expresses normally in plasma membrane. Furthermore, the AQP4-M1 but not the M23 isoform with P98A substitution in the first NPA motif can target to the plasma membrane, indicating an interaction of Nterminal sequence of AQP4-M1 with the first NPA motif. These results suggest that NPA motifs play a key role in plasma membrane expression of AQP4 but are not involved in AQP4 protein synthesis and degradation. The NPA motifs may interact with other structural domains in the regulation of membrane trafficking during aquaporin biogenesis.

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Section: Introductionmentioning

confidence: 99%

NPA motifs play a key role in plasma membrane targeting of aquaporin‐4

Guan

et al. 2010

IUBMB Life

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“…The aquaporins (AQPs) 2 are a family of membrane water channel proteins found throughout the animal and plant kingdoms (1,2). The AQPs characterized to date all exist as multisubunit oligomers (homotetrameric assemblies found in most AQPs), and this oligomerization is suggested to be important for their function (3,4).…”

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confidence: 99%

“…The AQPs characterized to date all exist as multisubunit oligomers (homotetrameric assemblies found in most AQPs), and this oligomerization is suggested to be important for their function (3,4). Almost all AQPs have two highly conserved Asn-Pro-Ala (NPA) motifs in each subunit, and these represent the signature motifs of the AQPs (1,2,5). Structural analysis of AQP1, the first AQP molecule to be identified, has shown that these motifs reside on opposite sides of the AQP1 monomer and are important for waterselective pore formation (2,3).…”

mentioning

confidence: 99%

“…So far, sequence analysis has revealed 13 functionally and phylogenetically distinct members of the AQP family in mammals, comprising three subgroups: the water-selective AQPs (AQP0, AQP1, AQP2, AQP4, AQP5, AQP6, and AQP8), aquaglyceroporins (AQP3, AQP7, AQP9, and AQP10), and a recently proposed third group (AQP11 and AQP12) (1,2,5). The water-selective AQPs are all permeated by water molecules, but AQP6 is additionally permeable to a wide range of anions, and AQP8 can facilitate the movement of ammonia and hydrogen peroxide across the plasma membrane (1,5).…”

mentioning

confidence: 99%

“…The water-selective AQPs are all permeated by water molecules, but AQP6 is additionally permeable to a wide range of anions, and AQP8 can facilitate the movement of ammonia and hydrogen peroxide across the plasma membrane (1,5). The aquaglyceroporins are characterized by permeability to water and neutral solutes, in particular glycerol (1,5).…”

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confidence: 99%

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The NPC Motif of Aquaporin-11, Unlike the NPA Motif of Known Aquaporins, Is Essential for Full Expression of Molecular Function

Ikeda¹,

Andoo²,

Shimono³

et al. 2011

Journal of Biological Chemistry

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The recently identified molecule aquaporin-11 (AQP11) has a unique amino acid sequence pattern that includes an AsnPro-Cys (NPC) motif, corresponding to the N-terminal AsnPro-Ala (NPA) signature motif of conventional AQPs. In this study, we examined the effect of the mutation of the NPC motif on the subcellular localization, oligomerization, and water permeability of AQP11 in transfected mammalian cells. Furthermore, the effect was also assessed using zebrafish. Sitedirected mutation at the NPC motif did not affect the subcellular localization of AQP11 but reduced its oligomerization. A cell swelling assay revealed that cells expressing AQP11 with a mutated NPC motif had significantly lower osmotic water permeability than cells expressing wild-type AQP11. Zebrafish deficient in endogenous AQP11 showed a deformity in the tail region at an early stage of development. This phenotype was dramatically rescued by injection of human wild-type AQP11 mRNA, whereas the effect of mRNA for AQP11 with a mutated NPC motif was less marked. Although the NPA motif is known to be important for formation of water-permeable pores by conventional AQPs, our observations suggest that the corresponding NPC motif of AQP11 is essential for full expression of molecular function.

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Aquaporins: Channels for the Molecule of Life

Hacke

Laur

2016

Encyclopedia of Life Sciences

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Liquid water has unique properties that make it a universal solvent. Water is an essential component of almost all physiological and biochemical reactions; therefore, its presence is required everywhere within an organism. The circulatory systems of animals and the vascular system of plants move fluids over long distances. In the tallest trees, water moves across a height gradient of 100 m or more, thereby connecting roots and distant leaves. On a cellular and tissue level, water movement is facilitated by intrinsic membrane proteins called aquaporins. These water channels are found in all life forms. Aquaporins have been mostly studied in mammals and plants, where water channels play important physiological roles. This article gives an overview of the discovery, structure and regulation of aquaporins. Their roles in different life forms are discussed. Key Concepts Water can diffuse through the lipid bilayer, but without aquaporins flow across membranes is slow. Aquaporins are integral membrane transport proteins, and they facilitate water movement in cells, tissues and entire organisms. A single water channel allows the passive passage of more than one billion water molecules per second. The aquaporin protein family is ancient, and aquaporins can be found in a wide range of organisms. Aquaporins appear to play important physiological roles in mammals, plants and other organisms.

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Discovery of the Aquaporins and Development of the Field

Cited by 191 publications

References 159 publications

NPA motifs play a key role in plasma membrane targeting of aquaporin‐4

NPA motifs play a key role in plasma membrane targeting of aquaporin‐4

The NPC Motif of Aquaporin-11, Unlike the NPA Motif of Known Aquaporins, Is Essential for Full Expression of Molecular Function

Aquaporins: Channels for the Molecule of Life

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