2D57

Double layered 2D crystal structure of AQUAPORIN-4 (AQP4M23) at 3.2 a resolution by electron crystallography

Summary for 2D57

• Entry DOI: 10.2210/pdb2d57/pdb
• Related: 1FQY 1J4N 1SOR 1YMG
• Descriptor: Aquaporin-4 (1 entity in total)
• Functional Keywords: water transport, water channel, aquaporin, two-dimensional crystal, membrane protein, baculovirus expression system, transport protein
• Biological source: Rattus norvegicus (Norway rat)
• Total number of polymer chains: 1
• Total formula weight: 32189.38

Authors

Hiroaki, Y.,Tani, K.,Kamegawa, A.,Gyobu, N.,Nishikawa, K.,Suzuki, H.,Walz, T.,Sasaki, S.,Mitsuoka, K.,Kimura, K.,Mizoguchi, A.,Fujiyoshi, Y. (deposition date: 2005-10-29, release date: 2006-01-31, Last modification date: 2023-11-08)

Primary citation

Hiroaki, Y.,Tani, K.,Kamegawa, A.,Gyobu, N.,Nishikawa, K.,Suzuki, H.,Walz, T.,Sasaki, S.,Mitsuoka, K.,Kimura, K.,Mizoguchi, A.,Fujiyoshi, Y.
Implications of the Aquaporin-4 Structure on Array Formation and Cell Adhesion
J.Mol.Biol., 355:628-639, 2005

PubMed Abstract: Aquaporin-4 (AQP4) is the predominant water channel in the mammalian brain and an important drug target for treatment of cerebral edema, bipolar disorder and mesial temporal lobe epilepsy. We determined the AQP4 structure by electron crystallography of double-layered, two-dimensional (2D) crystals. The structure allows us to discuss how the expression ratio between the long and short AQP4 splicing variant can determine the size of in vivo orthogonal arrays. Furthermore, AQP4 contains a short 3(10) helix in an extracellular loop, which mediates weak but specific interactions between AQP4 molecules in adjoining membranes. This finding suggests a previously unexpected role for AQP4 in cell adhesion. This notion was corroborated by expression of AQP4 in L-cells, which resulted in clustering of the cells. Our AQP4 structure thus enables us to propose models for the size regulation of orthogonal arrays and channel-mediated cell adhesion.

PubMed: 16325200
DOI: 10.1016/j.jmb.2005.10.081

Experimental method

ELECTRON CRYSTALLOGRAPHY (3.2 Å)