5DYE: Crystal Structure Of The Full Length S156e Mutant Of Human Aquaporin 5

Citation:
Abstract
Aquaporin membrane protein channels mediate cellular water flow. Human aquaporin 5 (AQP5) is highly expressed in the respiratory system and secretory glands where it facilitates the osmotically-driven generation of pulmonary secretions, saliva, sweat and tears. Dysfunctional trafficking of AQP5 has been implicated in several human disease states, including Sjogren's syndrome, bronchitis and cystic fibrosis. In order to investigate how the plasma membrane expression levels of AQP5 are regulated, we studied real-time translocation of GFP-tagged AQP5 in HEK293 cells. We show that AQP5 plasma membrane abundance in transfected HEK293 cells is rapidly and reversibly regulated by at least three independent mechanisms involving phosphorylation at Ser156, protein kinase A activity and extracellular tonicity. The crystal structure of a Ser156 phosphomimetic mutant indicates that its involvement in regulating AQP5 membrane abundance is not mediated by a conformational change of the carboxy-terminus. We suggest that together these pathways regulate cellular water flow.
PDB ID: 5DYEDownload
MMDB ID: 134575
PDB Deposition Date: 2015/9/24
Updated in MMDB: 2015/12
Experimental Method:
x-ray diffraction
Resolution: 3.5  Å
Source Organism:
Similar Structures:
Biological Unit for 5DYE: tetrameric; determined by author and by software (PISA)
Molecular Components in 5DYE
Label Count Molecule
Proteins (4 molecules)
4
Aquaporin-5(Gene symbol: AQP5)
Molecule annotation
Chemical (1 molecule)
1
1
* Click molecule labels to explore molecular sequence information.

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