5C5X

CRYSTAL STRUCTURE OF THE S156E MUTANT OF HUMAN AQUAPORIN 5

Summary for 5C5X

• Entry DOI: 10.2210/pdb5c5x/pdb
• Related: 3D9S
• Descriptor: Aquaporin-5, O-[(S)-{[(2S)-2-(hexanoyloxy)-3-(tetradecanoyloxy)propyl]oxy}(hydroxy)phosphoryl]-D-serine (3 entities in total)
• Functional Keywords: transport protein, membrane protein
• Biological source: Homo sapiens (Human)
• Cellular location: Apical cell membrane ; Multi-pass membrane protein : P55064
• Total number of polymer chains: 8
• Total formula weight: 207193.69

Authors

Kitchen, P.,Oeberg, F.,Sjoehamn, J.,Hedfalk, K.,Bill, R.M.,Conner, A.C.,Conner, M.T.,Toernroth-Horsefield, S. (deposition date: 2015-06-22, release date: 2015-12-02, Last modification date: 2024-01-10)

Primary citation

Kitchen, P.,Oberg, F.,Sjohamn, J.,Hedfalk, K.,Bill, R.M.,Conner, A.C.,Conner, M.T.,Tornroth-Horsefield, S.
Plasma Membrane Abundance of Human Aquaporin 5 Is Dynamically Regulated by Multiple Pathways.
Plos One, 10:e0143027-e0143027, 2015

PubMed 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 Sjögren'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.

PubMed: 26569106
DOI: 10.1371/journal.pone.0143027

Experimental method

X-RAY DIFFRACTION (2.6 Å)