8sjy

Structure of lens aquaporin-0 array in sphingomyelin/cholesterol bilayer (1SM:2Chol)

spinqualitylabelsall models 8sjy, resolution 2.35Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 8sjy is a 1 chain structure with sequence from Ovis aries. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron crystallography, Resolution 2.35Å Ligands: CLR, HWP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MIP_SHEEP Water channel. May be responsible for regulating the osmolarity of the lens. Interactions between homotetramers from adjoining membranes may stabilize cell junctions in the eye lens core. Publication Abstract from PubMed Aquaporin-0 (AQP0) tetramers form square arrays in lens membranes through a yet unknown mechanism, but lens membranes are enriched in sphingomyelin and cholesterol. Here, we determined electron crystallographic structures of AQP0 in sphingomyelin/cholesterol membranes and performed molecular dynamics (MD) simulations to establish that the observed cholesterol positions represent those seen around an isolated AQP0 tetramer and that the AQP0 tetramer largely defines the location and orientation of most of its associated cholesterol molecules. At a high concentration, cholesterol increases the hydrophobic thickness of the annular lipid shell around AQP0 tetramers, which may thus cluster to mitigate the resulting hydrophobic mismatch. Moreover, neighboring AQP0 tetramers sandwich a cholesterol deep in the center of the membrane. MD simulations show that the association of two AQP0 tetramers is necessary to maintain the deep cholesterol in its position and that the deep cholesterol increases the force required to laterally detach two AQP0 tetramers, not only due to protein-protein contacts but also due to increased lipid-protein complementarity. Since each tetramer interacts with four such 'glue' cholesterols, avidity effects may stabilize larger arrays. The principles proposed to drive AQP0 array formation could also underlie protein clustering in lipid rafts. Structure and dynamics of cholesterol-mediated aquaporin-0 arrays and implications for lipid rafts.,Chiu PL, Orjuela JD, de Groot BL, Aponte Santamaria C, Walz T Elife. 2024 Sep 2;12:RP90851. doi: 10.7554/eLife.90851. PMID:39222068 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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