Troponin I, cardiac muscle

Function

Troponin I is the inhibitory subunit of troponin, the thin filament regulatory complex which confers calcium-sensitivity to striated muscle actomyosin ATPase activity.

Classification

Family (Pfam)

PF00992 Troponin, PF11636 Troponin-I_N

InterPro

Troponin, Troponin-I_N, Troponin_I, Troponin_sf

Functional cluster

Mixed Regulatory & Membrane Proteins

Experimental structures · PDB · 39

• 1J1D X-ray 2.61A
• 1J1E X-ray 3.30A
• 1LXF NMR
• 1MXL NMR
• 1OZS NMR
• 2KGB NMR
• 2KRD NMR
• 2L1R NMR
• 2MZP NMR
• 2N7L NMR
• 4Y99 X-ray 2.00A
• 5VLN NMR
• … and 27 more

A predicted model is available from AlphaFold.

Gene Ontology · 25

• GO:0097512 cardiac myofibril
• GO:1990584 cardiac Troponin complex
• GO:0005829 cytosol
• GO:0030017 sarcomere
• GO:0005861 troponin complex
• GO:0003779 actin binding
• GO:0051015 actin filament binding
• GO:0019855 calcium channel inhibitor activity
• GO:0048306 calcium-dependent protein binding
• GO:0019904 protein domain specific binding
• GO:0019901 protein kinase binding
• GO:0030172 troponin C binding
• GO:0031014 troponin T binding
• GO:0060048 cardiac muscle contraction
• GO:0060047 heart contraction
• GO:0007507 heart development
• GO:0006874 intracellular calcium ion homeostasis
• GO:0030049 muscle filament sliding
• GO:0032780 negative regulation of ATP-dependent activity
• GO:0010882 regulation of cardiac muscle contraction by calcium ion signaling
• GO:0006940 regulation of smooth muscle contraction
• GO:0001980 regulation of systemic arterial blood pressure by ischemic conditions
• GO:0003009 skeletal muscle contraction
• GO:0001570 vasculogenesis
• GO:0055010 ventricular cardiac muscle tissue morphogenesis

Disease associations

• cardiomyopathy, familial restrictive, 1 MONDO:0007270
• dilated cardiomyopathy 2A MONDO:0012746
• dilated cardiomyopathy 1FF MONDO:0013211
• hypertrophic cardiomyopathy 7 MONDO:0013369

Drugs targeting this protein · 1

• LEVOSIMENDAN positive modulator

Related proteins · sequence + function similarity

• Troponin I, cardiac muscle 0.99
• Troponin I, cardiac muscle 0.99
• Troponin I, cardiac muscle 0.99
• Troponin I, cardiac muscle 0.98
• Troponin I, cardiac muscle 0.97
• Troponin I, cardiac muscle 0.96
• Troponin I, cardiac muscle 0.96
• Troponin I, slow skeletal muscle 0.88
• Troponin I, slow skeletal muscle 0.88
• Troponin I, slow skeletal muscle 0.85
• Troponin I, slow skeletal muscle 0.85
• Troponin I, fast skeletal muscle 0.84

Co-cited proteins · studied together in the literature

• Serine/threonine-protein kinase D1 1 shared papers
• Troponin I, cardiac muscle 1 shared papers
• Serine/threonine-protein kinase PAK 3 1 shared papers
• Troponin I, cardiac muscle 1 shared papers
• Myosin-binding protein C, cardiac-type 4 shared papers
• Troponin T, cardiac muscle 4 shared papers
• E3 ubiquitin-protein ligase TRIM63 1 shared papers
• Myosin-6 1 shared papers
• Myosin-7 4 shared papers
• Serine/threonine-protein kinase 4 1 shared papers
• RNA-binding protein 20 1 shared papers
• Myosin light chain 3 1 shared papers

Literature · 22 cited papers

• Multiple reaction monitoring to identify site-specific troponin I phosphorylated residues in the failing human heart. Circulation · 2012
• Clinical and mutational spectrum in a cohort of 105 unrelated patients with dilated cardiomyopathy. Eur. J. Med. Genet. · 2011
• Identification and functional characterization of cardiac troponin I as a novel disease gene in autosomal dominant dilated cardiomyopathy. Circ. Res. · 2009
• Phosphorylation of cardiac troponin I by mammalian sterile 20-like kinase 1. Biochem. J. · 2009
• Compound and double mutations in patients with hypertrophic cardiomyopathy: implications for genetic testing and counselling. J. Med. Genet. · 2005
• Muscle-specific RING finger 1 is a bona fide ubiquitin ligase that degrades cardiac troponin I. Proc. Natl. Acad. Sci. U.S.A. · 2004
• Protein kinase D is a novel mediator of cardiac troponin I phosphorylation and regulates myofilament function. Circ. Res. · 2004
• Novel mutation in cardiac troponin I in recessive idiopathic dilated cardiomyopathy. Lancet · 2004
• Mutation spectrum in a large cohort of unrelated consecutive patients with hypertrophic cardiomyopathy. Clin. Genet. · 2003
• Hypertrophic cardiomyopathy: distribution of disease genes, spectrum of mutations, and implications for a molecular diagnosis strategy. Circulation · 2003
• Idiopathic restrictive cardiomyopathy is part of the clinical expression of cardiac troponin I mutations. J. Clin. Invest. · 2003
• p21-activated kinase increases the calcium sensitivity of rat triton-skinned cardiac muscle fiber bundles via a mechanism potentially involving novel phosphorylation of troponin I. Circ. Res. · 2002
• … and 10 more in the literature graph