1ZSH

Crystal structure of bovine arrestin-2 in complex with inositol hexakisphosphate (IP6)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.250 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Nonvisual arrestin oligomerization and cellular localization are regulated by inositol hexakisphosphate binding

Milano, S.K.Kim, Y.M.Stefano, F.P.Benovic, J.L.Brenner, C.

(2006) J.Biol.Chem. 281: 9812-9823

  • DOI: 10.1074/jbc.M512703200

  • PubMed Abstract: 
  • Interactions between arrestins and phosphoinositides have been reported to regulate multiple membrane-associated signaling and trafficking events including clathrin-mediated endocytosis and light adaptation in Drosophila. Arrestins have been proposed ...

    Interactions between arrestins and phosphoinositides have been reported to regulate multiple membrane-associated signaling and trafficking events including clathrin-mediated endocytosis and light adaptation in Drosophila. Arrestins have been proposed to have nuclear and cytosolic functions as well, although the ligand dependence of these functions has not been investigated. Here we characterize the structural, molecular, and cellular interactions between arrestin-2 and inositol hexakisphosphate (inositol 1,2,3,4,5,6-hexakisphosphate (IP(6))). The crystal structure of the arrestin-2.IP(6) complex was solved to 2.9 A with crystal lattice contacts suggesting two sites on a protein monomer mediating IP(6) binding. Mutagenesis coupled to isothermal titration calorimetry and tritiated IP(6) binding assays confirmed two-site binding with a low affinity IP(6)-binding site in the N-domain and a high affinity site in the C-domain. Native gel electrophoresis, gel filtration, and analytical ultracentrifugation demonstrated the ability of IP(6) to promote arrestin-2 oligomerization via the two crystallographically defined ligand-binding locations. In addition, analysis in mammalian cells revealed that arrestin-2 not only undergoes homo-oligomerization, but it can also hetero-oligomerize with arrestin-3 in a manner that depends on IP(6)-binding sites. Mutation of either IP(6)-binding site in arrestin-2 disrupted oligomerization while interactions with known binding partners including clathrin, AP-2, and ERK2 were maintained. Subcellular localization studies showed that arrestin-2 oligomers are primarily cytoplasmic, whereas arrestin-2 monomers displayed increased nuclear localization. Thus, by promoting cytosolic oligomerization, IP(6) binding is proposed to be a negative regulator of interactions of arrestin with plasma membrane and nuclear signaling proteins.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Beta-arrestin 1
A
418Bos taurusMutation(s): 0 
Gene Names: ARRB1
Find proteins for P17870 (Bos taurus)
Go to Gene View: ARRB1
Go to UniProtKB:  P17870
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
IHP
Query on IHP

Download SDF File 
Download CCD File 
A
INOSITOL HEXAKISPHOSPHATE
C6 H18 O24 P6
IMQLKJBTEOYOSI-GPIVLXJGSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
IHPKd: 85 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.250 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 78.880α = 90.00
b = 78.880β = 90.00
c = 158.380γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-01-31
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance