4NEF

X-ray structure of human Aquaporin 2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.203 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

X-ray structure of human aquaporin 2 and its implications for nephrogenic diabetes insipidus and trafficking

Frick, A.Eriksson, U.K.de Mattia, F.Oberg, F.Hedfalk, K.Neutze, R.de Grip, W.J.Deen, P.M.Tornroth-Horsefield, S.

(2014) Proc Natl Acad Sci U S A 111: 6305-6310

  • DOI: 10.1073/pnas.1321406111
  • Primary Citation of Related Structures:  
    4NEF

  • PubMed Abstract: 
  • Human aquaporin 2 (AQP2) is a water channel found in the kidney collecting duct, where it plays a key role in concentrating urine. Water reabsorption is regulated by AQP2 trafficking between intracellular storage vesicles and the apical membrane. This process is tightly controlled by the pituitary hormone arginine vasopressin and defective trafficking results in nephrogenic diabetes insipidus (NDI) ...

    Human aquaporin 2 (AQP2) is a water channel found in the kidney collecting duct, where it plays a key role in concentrating urine. Water reabsorption is regulated by AQP2 trafficking between intracellular storage vesicles and the apical membrane. This process is tightly controlled by the pituitary hormone arginine vasopressin and defective trafficking results in nephrogenic diabetes insipidus (NDI). Here we present the X-ray structure of human AQP2 at 2.75 Å resolution. The C terminus of AQP2 displays multiple conformations with the C-terminal α-helix of one protomer interacting with the cytoplasmic surface of a symmetry-related AQP2 molecule, suggesting potential protein-protein interactions involved in cellular sorting of AQP2. Two Cd(2+)-ion binding sites are observed within the AQP2 tetramer, inducing a rearrangement of loop D, which facilitates this interaction. The locations of several NDI-causing mutations can be observed in the AQP2 structure, primarily situated within transmembrane domains and the majority of which cause misfolding and ER retention. These observations provide a framework for understanding why mutations in AQP2 cause NDI as well as structural insights into AQP2 interactions that may govern its trafficking.


    Organizational Affiliation

    Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Gothenburg, Sweden.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Aquaporin-2A, B, C, D242Homo sapiensMutation(s): 0 
Gene Names: AQP2
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for P41181 (Homo sapiens)
Explore P41181 
Go to UniProtKB:  P41181
PHAROS:  P41181
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CD
Query on CD

Download Ideal Coordinates CCD File 
E [auth A], G [auth D]CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
ZN
Query on ZN

Download Ideal Coordinates CCD File 
F [auth A]ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.203 
  • Space Group: P 42
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 119.11α = 90
b = 119.11β = 90
c = 90.621γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing
BUSTER-TNTrefinement
PDB_EXTRACTdata extraction
BUSTERrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-04-16
    Type: Initial release
  • Version 1.1: 2014-12-10
    Changes: Database references