Troponin C

{{short description|Protein family}} thumb|266x266px|Cardiac sarcomere structure, featuring troponin C thumb|261x261px|Troponin '''Troponin C''' ('''TN-C''' or '''TnC''') is a protein which is part of the troponin complex. There are two versions (paralogs) in humans. 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.

TnC is structually similar to calmodulin and myosin light chain. These three groups of proteins form a family.<ref>{{cite web |title=InterPro: IPR050230 Calmodulin/Myosin light chain/Troponin C-like |url=https://www.ebi.ac.uk/interpro/entry/InterPro/IPR050230/ |website=www.ebi.ac.uk}}</ref>

== Isoforms == {{Infobox protein | name = Troponin C, slow skeletal and cardiac muscles | AltNames = | image = | width = | caption = | Symbol = TNNC1 | AltSymbols = | EntrezGene = | HGNCid = 11943 | OMIM = 191040 | PDB = | RefSeq = NM_003280 | UniProt = P63316 | EC_number = | Chromosome = 3 | Arm = p | Band = 21.1 | LocusSupplementaryData = }} {{Infobox protein | name = Troponin C, skeletal muscle | AltNames = | image = | width = | caption = | Symbol = TNNC2 | AltSymbols = | EntrezGene = | HGNCid = 11944 | OMIM = 191039 | PDB = | RefSeq = NP_003270.1 | UniProt = P02585 | EC_number = | Chromosome = 20 | Arm = q | Band = 13.12 | LocusSupplementaryData = }}

The tissue specific subtypes are: * Slow troponin C, TNNC1 (3p21.1 {{OMIM|191040}}) * Fast troponin C, TNNC2 (20q12-q13.11, {{OMIM|191039}})

== See also == * Troponin * Troponin T * Troponin I * Calcium-binding protein * Sliding filament model

== References == {{Reflist}}

== External links == * {{MeshName|Troponin+C}}

{{Muscle tissue}} {{Cytoskeletal Proteins}} {{Calcium-binding proteins}}

Category:Troponin