Troponin

The troponins are three protein complexes that occur in skeletal and cardiac muscles of chordates. They each have three subunits, wherein the subunit C to bind calcium, T for the binding of tropomyosin and I responsible for the binding of actin (I for inhibitory, locking). Together with myosin and actin form these protein complexes movable ( contractile ) part of the musculature.

Biological Function

Bind calcium ion to troponin C, the complex changing its conformation and thus gives the Myosinbindungsstellen free, which allows for contraction. Troponin C is substantially homologous to calmodulin, which in the smooth muscle cells is primarily responsible for the binding of calcium ions.

Structure

There are three troponins, which are composed of eight different subunits, where the two known TN-C - subunits differ only slightly:

• Cardiac troponin, of cTnT, cTnI, TN -C
• Skeletal Troponin the white muscle from FTNT, fTnI, TN -C2
• Skeletal Troponin the red muscles, sTnT, STNi, TN -C

Pathology

Mutations in genes encoding any of the troponin subunits that can have hereditary diseases result in:

• CTnT: Hypertrophic cardiomyopathy ( CMH2 )
• Dilated cardiomyopathy ( CMD1D )
• Restrictive cardiomyopathy ( RCM3 )

• Hypertrophic cardiomyopathy ( CMH7 )
• Restrictive cardiomyopathy ( RCM1 )
• Dilated cardiomyopathy ( CMD2A )

• Dilated cardiomyopathy ( CMD1Z )
• Hypertrophic cardiomyopathy ( CMH13 )

• Cellular component
• Protein complex
• Protein group