Structure of the Aquaporin-0

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Structure of the Aquaporin-0 Membrane Junction
Tom Walz Department of Cell Biology Harvard
Medical School
Structure and Function of Large Molecular
Assemblies Erice June 2006
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The aquaporin family of water pores
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AQP0 forms thin junctions in vivo
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Two-dimensional crystallization of a membrane
protein
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Purification of AQP0 from the lens
Solubilization in 1 DM
Anion exchange (MonoQ)
Gel filtration (S12)
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2D crystals of AQP0
1 mm
2D crystal
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AQP0-mediated membrane junction
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The water pores in AQP1 and AQP0
AQP1
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Electron diffraction at liquid He temperature
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The 1.9 Å density map
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The AQP0 water pore at 1.9 Å resolution
Arg 187
Phe 48
Asn 164
Asn 68
His 66
Tyr 149
Phe 75
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The water pores in the 1.9 Å EM and 2.2 Å X-ray
structure
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Conformational switch of loop A upon proteolytic
cleavage
2.2 Å X-ray structure
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Conformational switch of loop A upon proteolytic
cleavage
2.2 Å X-ray structure
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Conformational switch of loop A upon proteolytic
cleavage
1.9 Å EM structure
2.2 Å X-ray structure
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Conformational switch of loop A upon proteolytic
cleavage
1.9 Å EM structure
2.2 Å X-ray structure
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Constriction site I - the ar/R site
AQP0
Arg 187
Ala 181
Phe 48
His 172
AQP1
Arg 197
Cys 191
Phe 58
His 182
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Molecular dynamics using AQPZ
UP
Arg 189
DOWN
Arg 189
Adapted from Wang et al. (2005) Structure 13
1107-1118
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Arg 187 and Met 176 in AQP0
1.9 Å EM structure
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Arg 187 and Met 176 in AQP0
1.9 Å EM structure
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The packing of AQP0 in the 2D crystals
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The packing of AQP0 in the 2D crystals
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The packing of AQP0 in the 2D crystals
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The lipids surrounding an AQP0 monomer
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Protein-lipid interactions
PC 1
PC 5
PC 6
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Collaborators
Harvard Medical School Tamir Gonen Yifan
Cheng Stephen Harrison Piotr Sliz