Titin mutations as the molecular basis for dilated cardiomyopathy.
Dilated cardiomyopathy (DCM) is a heterogeneous cardiac disease characterized by ventricular dilatation and systolic dysfunction. Recent genetic studies have revealed that mutations in genes for cardiac sarcomere components lead to DCM. The cardiac sarcomere consists of thick and thin filaments and a giant protein, titin. Because one of the loci of familial DCM was mapped to the region of the titin gene, we searched for titin mutations in the patients and identified four possible disease-associated mutations. Two mutations, Val54Met and Ala743Val, were found in the Z-line region of titin and decreased binding affinities of titin to Z-line proteins T-cap/telethonin and alpha-actinin, respectively, in yeast two-hybrid assays. The other two mutations were found in the cardiac-specific N2-B region of titin and one of them was a nonsense mutation, Glu4053ter, presumably encoding for a truncated nonfunctional molecule. These observations suggest that titin mutations may cause DCM in a subset of the patients.
Itoh-Satoh
Manatsu
M
Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
Hayashi
Takeharu
T
Nishi
Hirofumi
H
Koga
Yoshinori
Y
Arimura
Takuro
T
Koyanagi
Takeshi
T
Takahashi
Megumi
M
Hohda
Shigeru
S
Ueda
Kazuo
K
Nouchi
Tatsuhito
T
Hiroe
Michiaki
M
Marumo
Fumiaki
F
Imaizumi
Tsutomu
T
Yasunami
Michio
M
Kimura
Akinori
A
D000185:Actinin / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000235:genetics* / Q000378:metabolism; D002645:Chickens; D064211:Connectin; D004252:DNA Mutational Analysis; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011817:Rabbits; D012518:Sarcomeres / Q000378:metabolism; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques
D064211:Connectin; D009124:Muscle Proteins; C577292:TCAP protein, human; C577285:TTN protein, human; D000185:Actinin; D011494:Protein Kinases