Aquaporin
From Proteopedia
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== Function == | == Function == | ||
| - | '''Aquaporins''' are channel producing proteins which regulate the flow of water across the cell membrane | + | '''Aquaporins''' are channel producing proteins which regulate the flow of water across the cell membrane. The image on the left shows the protein, 6 molecules of glycerol and one of beta-octylglucoside.<br /> |
*'''Aquaporin-0''' functions as water channel in lens fibers.<br /> | *'''Aquaporin-0''' functions as water channel in lens fibers.<br /> | ||
*'''Aquaporin-1''' see details in [[Aquaporin-1]].<br /> | *'''Aquaporin-1''' see details in [[Aquaporin-1]].<br /> | ||
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*'''Aquaporin-5''' is implicated in the forming of saliva, tears and pulmonary secretions.<br /> | *'''Aquaporin-5''' is implicated in the forming of saliva, tears and pulmonary secretions.<br /> | ||
*'''Aquaporin-Z''' is a major water channel in bacteria.<br /> | *'''Aquaporin-Z''' is a major water channel in bacteria.<br /> | ||
| - | *'''Aquaglycerolporin''' is a water channel which can transport glycerol, urea and other small solutes.<br /> | + | *'''Aquaglycerolporin''' (GLpf) is a water channel which can transport glycerol, polyalcohols, urea and other small solutes.<br /> |
== Disease == | == Disease == | ||
Revision as of 10:49, 4 November 2015
Contents |
Function
Aquaporins are channel producing proteins which regulate the flow of water across the cell membrane. The image on the left shows the protein, 6 molecules of glycerol and one of beta-octylglucoside.
- Aquaporin-0 functions as water channel in lens fibers.
- Aquaporin-1 see details in Aquaporin-1.
- Aquaporin-2 function is to reabsorb water from urine in the kidney.
- Aquaporin-3 function is to promote glycerol permeability across cell membrane.
- Aquaporin-4 regulates water balance in the central nervous system.
- Aquaporin-5 is implicated in the forming of saliva, tears and pulmonary secretions.
- Aquaporin-Z is a major water channel in bacteria.
- Aquaglycerolporin (GLpf) is a water channel which can transport glycerol, polyalcohols, urea and other small solutes.
Disease
Mutations in aquaporin-2 cause diabitis insipidus. Mutations in aquaporin-0 in mice cause congenital cataracts. Aquaporin-4 is the primary autoimmune target of neuromyelitis optica.
Structural highlights
Aquaporins are made of α-helix bundles. The water transporting channel contains 2 restriction sites conferring an hourglass model to the channel. Two NPA motifs from opposite surfaces form one restriction. Another restriction is formed by a cluster of aromatic/arginine side chains which serves to weaken the hydrogen bonding between water molecules.
3D Structures of Aquaporin
Updated on 04-November-2015
Proteopedia Page Contributors and Editors (what is this?)
Michal Harel, Alexander Berchansky, Mark Leiserson, David Canner, Jaime Prilusky, Eran Hodis
