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The three-dimensional structure of aquaporin-1.
- Source :
-
Nature [Nature] 1997 Jun 05; Vol. 387 (6633), pp. 624-7. - Publication Year :
- 1997
-
Abstract
- The entry and exit of water from cells is a fundamental process of life. Recognition of the high water permeability of red blood cells led to the proposal that specialized water pores exist in the plasma membrane. Expression in Xenopus oocytes and functional studies of an erythrocyte integral membrane protein of relative molecular mass 28,000, identified it as the mercury-sensitive water channel, aquaporin-1 (AQP1). Many related proteins, all belonging to the major intrinsic protein (MIP) family, are found throughout nature. AQP1 is a homotetramer containing four independent aqueous channels. When reconstituted into lipid bilayers, the protein forms two-dimensional lattices with a unit cell containing two tetramers in opposite orientation. Here we present the three-dimensional structure of AQP1 determined at 6A resolution by cryo-electron microscopy. Each AQP1 monomer has six tilted, bilayer-spanning alpha-helices which form a right-handed bundle surrounding a central density. These results, together with functional studies, provide a model that identifies the aqueous pore in the AQP1 molecule and indicates the organization of the tetrameric complex in the membrane.
- Subjects :
- Animals
Aquaporin 1
Blood Proteins chemistry
Blood Proteins ultrastructure
Erythrocytes chemistry
Ion Channels ultrastructure
Membrane Proteins chemistry
Membrane Proteins ultrastructure
Models, Molecular
Recombinant Proteins chemistry
Xenopus
Aquaporins
Ion Channels chemistry
Protein Conformation
Subjects
Details
- Language :
- English
- ISSN :
- 0028-0836
- Volume :
- 387
- Issue :
- 6633
- Database :
- MEDLINE
- Journal :
- Nature
- Publication Type :
- Academic Journal
- Accession number :
- 9177353
- Full Text :
- https://doi.org/10.1038/42512