Aquaporin

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== Function ==
== Function ==
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'''Aquaporins''' are channel producing proteins which regulate the flow of water across the cell membrane. More details of '''aquaporin-1''' in [[Aquaporin-1]]. '''Aquaglyceroporin''' (GLpf) conducts water and polyalcohols. The image on the left shows the protein, 6 molecules of glycerol and one of beta-octylglucoside.<br />
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'''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 />
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*'''Aquaglycerolporin''' is a water channel which can transport glycerol, urea and other small solutes.<br />
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*'''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

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Crystal Structure of Human Aquaporin 4, 3gd8
Crystal Structure of Human Aquaporin 4, 3gd8















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


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