In vitro functional analyses of arrhythmogenic right ventricular cardiomyopathy-associated desmoglein-2-missense variations.
BACKGROUND
Although numerous sequence variants in desmoglein-2 (DSG2) have been associated with arrhythmogenic right ventricular cardiomyopathy (ARVC), the functional impact of new sequence variations is difficult to estimate.


RESULTS
To test the functional consequences of DSG2-variants, we established an expression system for the extracellular domain and the full-length DSG2 using the human cell line HT1080. We established new tools to investigate ARVC-associated DSG2 variations and compared wild-type proteins and proteins with one of the five selected variations (DSG2-p.R46Q, -p.D154E, -p.D187G, -p.K294E, -p.V392I) with respect to prodomain cleavage, adhesion properties and cellular localisation.


CONCLUSIONS
The ARVC-associated DSG2-p.R46Q variation was predicted to be probably damaging by bioinformatics tools and to concern a conserved proprotein convertase cleavage site. In this study an impaired prodomain cleavage and an influence on the DSG2-properties could be demonstrated for the R46Q-variant leading to the classification of the variant as a potential gain-of-function mutant. In contrast, the variants DSG2-p.K294E and -p.V392I, which have an arguable impact on ARVC pathogenesis and are predicted to be benign, did not show functional differences to the wild-type protein in our study. Notably, the variants DSG2-p.D154E and -p.D187G, which were predicted to be damaging by bioinformatics tools, had no detectable effects on the DSG2 protein properties in our study.
Erich and Hanna Klessmann Institute for Cardiovascular Research and Development, Clinic of Thoracic and Cardiovascular Surgery, Heart and Diabetes Centre NRW, Ruhr-University Bochum, Bad Oeynhausen, Germany.
Anna
A
Gaertner
Baerbel
B
Klauke
Ines
I
Stork
Karsten
K
Niehaus
Gesa
G
Niemann
Jan
J
Gummert
Hendrik
H
Milting
D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000235:genetics*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D051301:Desmoglein 2 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D020125:Mutation, Missense; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
C495314:DSG2 protein, human; D051301:Desmoglein 2; D011994:Recombinant Proteins; D002118:Calcium