Fast Skeletal Troponin T (Fast Sktnt) (skTnT) Recombinant Protein

The binding of Ca(2+) to the trimeric troponin complex initiates the process of muscle contraction. Increased Ca(2+) concentrations produce a conformational change in the troponin complex that is transmitted to tropomyosin dimers situated along actin filaments. The altered conformation permits increased interaction between a myosin head and an actin filament which, ultimately, produces a muscle contraction. The troponin complex has protein subunits C, I, and T. Subunit C binds Ca(2+) and subunit I binds to actin and inhibits actin-myosin interaction. Subunit T binds the troponin complex to the tropomyosin complex and is also required for Ca(2+)-mediated activation of actomyosin ATPase activity. There are 3 different troponin T genes that encode tissue-specific isoforms of subunit T for fast skeletal-, slow skeletal-, and cardiac-muscle. This gene encodes fast skeletal troponin T protein; also known as troponin T type 3. Alternative splicing results in multiple transcript variants encoding additional distinct troponin T type 3 isoforms. A developmentally regulated switch between fetal/neonatal and adult troponin T type 3 isoforms occurs. Additional splice variants have been described but their biological validity has not been established. Mutations in this gene may cause distal arthrogryposis multiplex congenita type 2B (DA2B). [provided by RefSeq, Oct 2009]

TNNT3: Troponin T is the tropomyosin-binding subunit of troponin, the thin filament regulatory complex which confers calcium-sensitivity to striated muscle actomyosin ATPase activity. Defects in TNNT3 are a cause of distal arthrogryposis type 2B (DA2B); also known as arthrogryposis multiplex congenita, distal, type 2B (AMCD2B). DA2B is a form of inherited multiple congenital contractures. Affected individuals have vertical talus, ulnar deviation in the hands, severe camptodactyly, and a distinctive face characterized by a triangular shape, prominent nasolabial folds, small mouth and a prominent chin. Belongs to the troponin T family. 7 isoforms of the human protein are produced by alternative splicing.

Protein type: Motility/polarity/chemotaxis; Motor

Chromosomal Location of Human Ortholog: 11p15.5

Cellular Component: cytosol; troponin complex

Molecular Function: actin binding; calcium-dependent ATPase activity; calcium-dependent protein binding; tropomyosin binding; troponin C binding; troponin I binding

Biological Process: muscle filament sliding; regulation of ATPase activity; regulation of striated muscle contraction; skeletal muscle contraction

Disease: Arthrogryposis, Distal, Type 2b