Structure of full length telethonin in complex with the N-terminus of titin
[TELT_HUMAN] Defects in TCAP are a cause of familial hypertrophic cardiomyopathy (CMH) [MIM:192600]; also designated FHC or HCM. Familial hypertrophic cardiomyopathy is a hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death. Defects in TCAP are a cause of limb-girdle muscular dystrophy type 2G (LGMD2G) [MIM:601954]. LGMD2G is an autosomal recessive degenerative myopathy characterized by proximal and distal muscle weakness and atrophy in the limbs, dystrophic changes on muscle biopsy, and absence of telethonin. Cardiac muscle is involved in a subset of patients. Defects in TCAP are the cause of cardiomyopathy dilated type 1N (CMD1N) [MIM:607487]. Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death.  
[TELT_HUMAN] Muscle assembly regulating factor. Mediates the antiparallel assembly of titin (TTN) molecules at the sarcomeric Z-disk.
Publication Abstract from PubMed
The Z-disk region defines the lateral boundary of the sarcomere and requires a high level of mechanical strength to provide a stable framework for large filamentous muscle proteins. The level of complexity at this area is reflected by a large number of protein-protein interactions. Recently, we unraveled how the N-terminus of the longest filament component, the giant muscle protein titin, is assembled into an antiparallel (2:1) sandwich complex by the N-terminal titin-binding segment of the Z-disk ligand telethonin/T-cap [Zou, P., Pinotsis, N., Lange, S., Song, Y.H., Popov, A., Mavridis, I., Mayans, O.M., Gautel, M., Wilmanns, M., 2006. Palindromic assembly of the giant muscle protein titin in the sarcomeric Z-disk. Nature 439, 229-233]. In this contribution, we present structural data of a related complex of the titin N-terminus with full-length telethonin. The C-terminus of telethonin remains invisible, suggesting that it does not fold into a defined structure even in the presence of titin. In contrast to the structure with truncated telethonin, a dimer of two titin/telethonin complexes is formed within the crystal environment, potentially indicating the formation of higher oligomers. We further investigated the structure and dynamics of this assembly by small-angle X-ray scattering, circular dichroism, and in vivo complementation data. The data consistently indicate the involvement of the C-terminal part of telethonin into the assembly of two titin/telethonin complexes.
Evidence for a dimeric assembly of two titin/telethonin complexes induced by the telethonin C-terminus.,Pinotsis N, Petoukhov M, Lange S, Svergun D, Zou P, Gautel M, Wilmanns M J Struct Biol. 2006 Aug;155(2):239-50. Epub 2006 Apr 27. PMID:16713295
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.