Aquaglyceroporins, one channel for two molecules.
In the light of the recently published structure of GlpF and AQP1, we have analysed the nature of the residues which could be involved in the formation of the selectivity filter of aquaporins, glycerol facilitators and aquaglyceroporins. We demonstrate that the functional specificity for major intrinsic protein (MIP) channels can be explained on one side by analysing the polar environment of the residues that form the selective filter. On the other side, we show that the channel selectivity could be associated with the oligomeric state of the membrane protein. We conclude that a non-polar environment in the vicinity of the top of helix 5 could allow aquaglyceroporins and GlpF to exist as monomers within the hydrophobic environment of the membrane.
UMR CNRS 6026, Interactions Cellulaires et Moléculaires, Equipe Canaux et Récepteurs Membranaires, Université de Rennes 1, Rennes, France. daniel.thomas@univ-rennes1.fr
Daniel
D
Thomas
Patrick
P
Bron
Grégory
G
Ranchy
Laurence
L
Duchesne
Annie
A
Cavalier
Jean-Paul
JP
Rolland
Céline
C
Raguénès-Nicol
Jean-François
JF
Hubert
Winfried
W
Haase
Christian
C
Delamarche
D000818:Animals; D051398:Aquaporin 1; D020346:Aquaporins / Q000737:chemistry*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000737:chemistry; D005614:Freeze Fracturing; D005990:Glycerol / Q000737:chemistry; D013294:Lactococcus lactis / Q000737:chemistry* / Q000235:genetics; D008565:Membrane Proteins; D008854:Microscopy, Electron; D008958:Models, Molecular; D009865:Oocytes / Q000378:metabolism; D010316:Particle Size; D014867:Water / Q000737:chemistry; D014981:Xenopus
D020346:Aquaporins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C106425:aqpZ protein, E coli; D014867:Water; C078043:GlpF protein, E coli; D051398:Aquaporin 1; D005990:Glycerol