Crystal structure of the stable degradation fragment of human plakophilin 2 isoform a (PKP2a) C752R variant

Experimental Data Snapshot

  • Resolution: 1.55 Å
  • R-Value Free: 0.192 
  • R-Value Work: 0.158 
  • R-Value Observed: 0.160 

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Molecular insights into arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 missense mutations.

Kirchner, F.Schuetz, A.Boldt, L.H.Martens, K.Dittmar, G.Haverkamp, W.Thierfelder, L.Heinemann, U.Gerull, B.

(2012) Circ Cardiovasc Genet 5: 400-411

  • DOI: https://doi.org/10.1161/CIRCGENETICS.111.961854
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiac disorder mainly caused by dominant mutations in several components of the cardiac desmosome including plakophilin-2 (PKP2), the most prevalent disease gene. Little is known about the underlying genetic and molecular mechanisms of missense mutations located in the armadillo (ARM) domains of PKP2, as well as their consequences on human cardiac pathology. We focused on in vivo and in vitro studies of the PKP2 founder mutation c.2386T>C (p.C796R), and demonstrated in cardiac tissue from 2 related mutation carriers a patchy expression pattern ranging from unchanged to totally absent immunoreactive signals of PKP2 and other desmosomal proteins. In vitro expression analysis of mutant PKP2 in cardiac derived HL-1 cells revealed unstable proteins that fail to interact with desmoplakin and are targeted by degradation involving calpain proteases. Bacterial expression, crystallization, and structural modeling of mutated proteins impacting different ARM domains and helices of PKP2 confirmed their instability and degradation, resulting in the same remaining protein fragment that was crystallized and used to model the entire ARM domain of PKP2. The p.C796R and other ARVC-related PKP2 mutations indicate loss of function effects by intrinsic instability and calpain proteases mediated degradation in in vitro model systems, suggesting haploinsufficiency as the most likely cause for the genesis of dominant ARVC due to mutations in PKP2.

  • Organizational Affiliation

    Helmholtz-Protein Sample Production Facility, Berlin, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Plakophilin-2233Homo sapiensMutation(s): 0 
Gene Names: PKP2
UniProt & NIH Common Fund Data Resources
Find proteins for Q99959 (Homo sapiens)
Explore Q99959 
Go to UniProtKB:  Q99959
PHAROS:  Q99959
GTEx:  ENSG00000057294 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ99959
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.55 Å
  • R-Value Free: 0.192 
  • R-Value Work: 0.158 
  • R-Value Observed: 0.160 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.35α = 90
b = 63.038β = 90
c = 74.953γ = 90
Software Package:
Software NamePurpose
MxCuBEdata collection
XDSdata reduction
XDSdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-08-01
    Type: Initial release
  • Version 1.1: 2012-09-05
    Changes: Database references
  • Version 1.2: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 1.3: 2024-03-13
    Changes: Source and taxonomy