Titin (TTN), Partial (TTN) Human Recombinant Protein

This gene encodes a large abundant protein of striated muscle. The product of this gene is divided into two regions, a N-terminal I-band and a C-terminal A-band. The I-band, which is the elastic part of the molecule, contains two regions of tandem immunoglobulin domains on either side of a PEVK region that is rich in proline, glutamate, valine and lysine. The A-band, which is thought to act as a protein-ruler, contains a mixture of immunoglobulin and fibronectin repeats, and possesses kinase activity. An N-terminal Z-disc region and a C-terminal M-line region bind to the Z-line and M-line of the sarcomere, respectively, so that a single titin molecule spans half the length of a sarcomere. Titin also contains binding sites for muscle associated proteins so it serves as an adhesion template for the assembly of contractile machinery in muscle cells. It has also been identified as a structural protein for chromosomes. Alternative splicing of this gene results in multiple transcript variants. Considerable variability exists in the I-band, the M-line and the Z-disc regions of titin. Variability in the I-band region contributes to the differences in elasticity of different titin isoforms and, therefore, to the differences in elasticity of different muscle types. Mutations in this gene are associated with familial hypertrophic cardiomyopathy 9, and autoantibodies to titin are produced in patients with the autoimmune disease scleroderma. [provided by RefSeq, Feb 2012]

Titin: a protein kinase that is abundant in striated muscle. Is divided into two regions, a N-terminal I-band and a C-terminal A-band. The I-band, which is the elastic part of the molecule, contains two regions of tandem immunoglobulin domains on either side of a PEVK region that is rich in proline, glutamate, valine and lysine. The A-band, which is thought to act as a protein-ruler, contains a mixture of immunoglobulin and fibronectin repeats, and possesses kinase activity. A N-terminal Z-disc region and a C-terminal M-line region bind to the Z-line and M-line of the sarcomere respectively so that a single titin molecule spans half the length of a sarcomere. Titin also contains binding sites for muscle associated proteins so it serves as an adhesion template for the assembly of contractile machinery in muscle cells. It has also been identified as a structural protein for chromosomes. Mutations are associated with familial hypertrophic cardiomyopathy 9 and autoantibodies to titin are produced in patients with the autoimmune disease scleroderma.

Protein type: Kinase, protein; Protein kinase, CAMK; Protein kinase, Ser/Thr (non-receptor); EC 2.7.11.1; CAMK group; MLCK family

Chromosomal Location of Human Ortholog: 2q31

Cellular Component: condensed nuclear chromosome; cytosol; extracellular region; I band; M band; muscle myosin complex; striated muscle thin filament; Z disc

Molecular Function: actin filament binding; actinin binding; ATP binding; calcium ion binding; calmodulin binding; enzyme binding; identical protein binding; muscle alpha-actinin binding; protease binding; protein binding; protein kinase binding; protein self-association; protein serine/threonine kinase activity; protein-tyrosine kinase activity; structural constituent of muscle; telethonin binding

Biological Process: blood coagulation; cardiac muscle contraction; cardiac muscle fiber development; cardiac muscle morphogensis; cardiac myofibril assembly; mitotic chromosome condensation; muscle contraction; muscle filament sliding; muscle thick filament assembly; muscle thin filament assembly; peptidyl-tyrosine phosphorylation; platelet activation; platelet degranulation; regulation of catalytic activity; regulation of protein kinase activity; response to calcium ion; sarcomere organization; sarcomerogenesis; striated muscle contraction

Disease: Cardiomyopathy, Dilated, 1g; Hereditary Myopathy With Early Respiratory Failure; Muscular Dystrophy, Limb-girdle, Type 2j; Myopathy, Early-onset, With Fatal Cardiomyopathy; Tibial Muscular Dystrophy, Tardive