3SUI

Crystal structure of ca2+-calmodulin in complex with a trpv1 c-terminal peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.192 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Distinct properties of Ca2+-calmodulin binding to N- and C-terminal regulatory regions of the TRPV1 channel.

Lau, S.Y.Procko, E.Gaudet, R.

(2012) J.Gen.Physiol. 140: 541-555

  • DOI: 10.1085/jgp.201210810

  • PubMed Abstract: 
  • Transient receptor potential (TRP) vanilloid 1 (TRPV1) is a molecular pain receptor belonging to the TRP superfamily of nonselective cation channels. As a polymodal receptor, TRPV1 responds to heat and a wide range of chemical stimuli. The influx of ...

    Transient receptor potential (TRP) vanilloid 1 (TRPV1) is a molecular pain receptor belonging to the TRP superfamily of nonselective cation channels. As a polymodal receptor, TRPV1 responds to heat and a wide range of chemical stimuli. The influx of calcium after channel activation serves as a negative feedback mechanism leading to TRPV1 desensitization. The cellular calcium sensor calmodulin (CaM) likely participates in the desensitization of TRPV1. Two CaM-binding sites are identified in TRPV1: the N-terminal ankyrin repeat domain (ARD) and a short distal C-terminal (CT) segment. Here, we present the crystal structure of calcium-bound CaM (Ca(2+)-CaM) in complex with the TRPV1-CT segment, determined to 1.95-Å resolution. The two lobes of Ca(2+)-CaM wrap around a helical TRPV1-CT segment in an antiparallel orientation, and two hydrophobic anchors, W787 and L796, contact the C-lobe and N-lobe of Ca(2+)-CaM, respectively. This structure is similar to canonical Ca(2+)-CaM-peptide complexes, although TRPV1 contains no classical CaM recognition sequence motif. Using structural and mutational studies, we established the TRPV1 C terminus as a high affinity Ca(2+)-CaM-binding site in both the isolated TRPV1 C terminus and in full-length TRPV1. Although a ternary complex of CaM, TRPV1-ARD, and TRPV1-CT had previously been postulated, we found no biochemical evidence of such a complex. In electrophysiology studies, mutation of the Ca(2+)-CaM-binding site on TRPV1-ARD abolished desensitization in response to repeated application of capsaicin, whereas mutation of the Ca(2+)-CaM-binding site in TRPV1-CT led to a more subtle phenotype of slowed and reduced TRPV1 desensitization. In summary, our results show that the TRPV1-ARD is an important mediator of TRPV1 desensitization, whereas TRPV1-CT has higher affinity for CaM and is likely involved in separate regulatory mechanisms.


    Organizational Affiliation

    Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
A
149Homo sapiensMutation(s): 0 
Gene Names: CALM1 (CALM, CAM, CAM1)
Find proteins for P0DP23 (Homo sapiens)
Go to Gene View: CALM1
Go to UniProtKB:  P0DP23
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Transient receptor potential cation channel subfamily V member 1
B
37Rattus norvegicusMutation(s): 0 
Gene Names: Trpv1 (Vr1, Vr1l)
Find proteins for O35433 (Rattus norvegicus)
Go to UniProtKB:  O35433
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.192 
  • Space Group: P 61 2 2
Unit Cell:
Length (Å)Angle (°)
a = 41.681α = 90.00
b = 41.681β = 90.00
c = 341.533γ = 120.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
MOLREPphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2011-07-11 
  • Released Date: 2012-09-12 
  • Deposition Author(s): Lau, S.-Y., Gaudet, R.

Revision History 

  • Version 1.0: 2012-09-12
    Type: Initial release
  • Version 1.1: 2012-11-14
    Type: Database references
  • Version 1.2: 2017-11-08
    Type: Refinement description