A Cypher/ZASP mutation associated with dilated cardiomyopathy alters the binding affinity to protein kinase C.
Dilated cardiomyopathy is characterized by ventricular dilation with systolic dysfunction of cardiac muscle. Recent genetic studies have revealed that mutations in genes for cytoskeleton proteins distributed in the Z-disc and/or intercalated discs of the cardiac muscle are major predictors of cardiomyopathy. However, as mutations in these genes can account for only a part of the patient population, there should be another disease-causing gene(s) for cardiomyopathy. Cypher/ZASP appears to be an ideal candidate for the cardiomyopathy causative gene, because Cypher/ZASP encodes a Z-disc associated protein, and recent studies have demonstrated that Cypher/ZASP knock-out mice develop cardiomyopathy. In this study, we searched for sequence variations in Cypher/ZASP in 96 unrelated Japanese patients with dilated cardiomyopathy. A D626N mutation located within the third LIM domain was identified in a familial case but not found in the unrelated controls. A family study of the patient showed that all affected siblings tested had the same mutation. Clinical information of the affected family members suggested that the mutation was associated with late onset cardiomyopathy. To reveal the biochemical changes due to the mutation, we performed a yeast two-hybrid assay and a pull-down assay. It was demonstrated by both assays that the D626N mutation of Cypher/ZASP increased the affinity of the LIM domain for protein kinase C, suggesting a novel biochemical mechanism of the pathogenesis of dilated cardiomyopathy.
Arimura
Takuro
T
Department of Molecular Pathogenesis, Medical Research Institute, and Laboratory of Genome Diversity, School of Biomedical Science, Tokyo Medical and Dental University, Tokyo 101-0062, Japan.
Hayashi
Takeharu
T
Terada
Hajime
H
Lee
Su-Yeoun
SY
Zhou
Qiang
Q
Takahashi
Megumi
M
Ueda
Kazuo
K
Nouchi
Tatsuhito
T
Hohda
Shigeru
S
Shibutani
Makoto
M
Hirose
Masao
M
Chen
Ju
J
Park
Jeong-Euy
JE
Yasunami
Michio
M
Hayashi
Hideharu
H
Kimura
Akinori
A
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D003599:Cytoskeleton / Q000378:metabolism; D004252:DNA Mutational Analysis; D018076:DNA, Complementary / Q000378:metabolism; D005260:Female; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D060588:LIM Domain Proteins; D008297:Male; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010957:Plasmids / Q000378:metabolism; D018807:Polymorphism, Single-Stranded Conformational; D011233:Precipitin Tests; D011485:Protein Binding; D020033:Protein Isoforms; D011493:Protein Kinase C / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018076:DNA, Complementary; D018398:Homeodomain Proteins; C120696:LDB3 protein, human; D060588:LIM Domain Proteins; C485639:Ldb3 protein, mouse; D020033:Protein Isoforms; D011493:Protein Kinase C