Troponin C is a protein which is part of the troponin complex. It contains four calcium-binding EF hands, although different isoforms may have fewer than four functional calcium-binding subdomains. It is a component of thin filaments, along with actin and tropomyosin. It contains an N lobe and a C lobe. The C lobe serves a structural purpose and binds to the N domain of troponin I (TnI). The C lobe can bind either Ca2+ or Mg2+. The N lobe, which binds only Ca2+, is the regulatory lobe and binds to the C domain of troponin I after calcium binding.

Cardiac sarcomere structure, featuring troponin C
Troponin C
Test ofTroponin
Troponin

Isoforms

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Troponin C, slow skeletal and cardiac muscles
Identifiers
SymbolTNNC1
HGNC11943
OMIM191040
RefSeqNM_003280
UniProtP63316
Other data
LocusChr. 3 p21.1
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StructuresSwiss-model
DomainsInterPro
Troponin C, skeletal muscle
Identifiers
SymbolTNNC2
HGNC11944
OMIM191039
RefSeqNP_003270.1
UniProtP02585
Other data
LocusChr. 20 q13.12
Search for
StructuresSwiss-model
DomainsInterPro

The tissue specific subtypes are:

Mutations

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Point mutations can occur in troponin C inducing alterations to Ca2+ and Mg2+ binding and protein structure,[1] leading to abnormalities in muscle contraction.[2][3] In cardiac muscle, they are related to dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM).

These known point mutations are:

See also

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References

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  1. ^ Kalyva A, Parthenakis FI, Marketou ME, Kontaraki JE, Vardas PE (April 2014). "Biochemical characterisation of Troponin C mutations causing hypertrophic and dilated cardiomyopathies". Journal of Muscle Research and Cell Motility. 35 (2): 161–78. doi:10.1007/s10974-014-9382-0. PMID 24744096. S2CID 1726747.
  2. ^ Cheng Y, Regnier M (July 2016). "Cardiac troponin structure-function and the influence of hypertrophic cardiomyopathy associated mutations on modulation of contractility". Archives of Biochemistry and Biophysics. Special Issue: Myofilament Modulation of Contraction. 601: 11–21. doi:10.1016/j.abb.2016.02.004. PMC 4899195. PMID 26851561.
  3. ^ Pinto JR, Parvatiyar MS, Jones MA, Liang J, Ackerman MJ, Potter JD (July 2009). "A functional and structural study of troponin C mutations related to hypertrophic cardiomyopathy". The Journal of Biological Chemistry. 284 (28): 19090–100. doi:10.1074/jbc.M109.007021. PMC 2707221. PMID 19439414.
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