Cardiac troponin C (C-TnC) was labeled with the sulfhydryl-specific fluorescent probe molecule 2-(4'-iodoacetamidoanilino)naphthalene-6-sulfonic acid at cysteine 35 and 84 to produce C-TnCIA. This modified protein binds Ca2+, undergoes Ca2+-induced increases in alpha helix, and forms a complex with other troponin subunits as does unlabeled C-TnC. C-TnCIA undergoes a small fluorescence decrease ...

The extracellular matrix protein tenascin C (TnC) is expressed in a variety of embryonic tissues, but its expression in adult arteries is co-incident with sites of vascular disease. TnC expression has been linked to the development and complications of intimal hyperplasia, pulmonary artery hypertension, atherosclerosis, myocardial infarction, and heart failure. This review identifies the growin...

Single fibers of rat diaphragm containing different naturally occurring combinations of myofibrillar protein isoforms were used to evaluate the contribution of troponin C (TnC) isoforms to fiber type-related differences with respect to sensitivity to Sr(2+) of the contractile system. Mechanically skinned fibers were studied for their isometric force vs. Sr(2+) concentration ([Sr(2+)]) relations...

Tenascin-C (TNC), overexpressed in invasive growths, has been implicated in progression of melanoma, but the source and function of this molecule are not well defined. We found TNC expression at the front of invading melanoma cells, and that adding TNC to matrices enhances individual melanoma cell migration. As TNC is a multidomain protein, we examined the role of the TNC EGF-like (EGFL) repeat...

For many ligands of the TNF family, trimer stability and oligomerization status are crucial determinants of receptor activation. However, for the immunostimulatory ligands CD27L, CD40L, 41BBL, and glucocorticoid-induced TNF receptor ligand (GITRL) detailed information regarding these requirements is lacking. Here, we comprehensively evaluated the effect of trimer stability and oligomerization o...

Troponin and its Ca(2+)-binding subunit troponin C (TnC) of the Ezo-giant scallop, Patinopecten yessoensis, have been revealed to bind only 1 mol of Ca2+/mol irrespective of the presence and absence of Mg2+. The amino acid sequence of the TnC has been determined by the automated Edman degradation. TnC is composed of 152 residues including 3 tryptophans at positions 53, 70, and 109, 4 cysteines ...

While calcium binding to troponin C (TnC) triggers the contraction of both skeletal and cardiac muscle, there is clear evidence that different mechanisms may be involved. For example, activation of heart myofilaments occurs with binding to a single regulatory site on TnC, whereas activation of fast skeletal myofilaments occurs with binding to two regulatory sites. The physiological difference b...

Skeletal muscle troponin C (TNC) is structured into two separate domains linked by a nine-turn alpha-helix (D/E helix). It has been demonstrated that calcium binding to the regulatory sites within the N-terminal domain induces conformational changes in the C-terminal domain of isolated TNC. Since the only contact between the two domains is the long D/E helix, the transfer of information must in...

Troponin (Tn) is an important regulatory protein in the thin-filament complex of cardiomyocytes. Calcium binding to the troponin C (TnC) subunit causes a change in its dynamics that leads to the transient opening of a hydrophobic patch on TnC's surface, to which a helix of another subunit, troponin I (TnI), binds. This process initiates contraction, making it an important target for studies inv...