Abstract
1. Troponin I isolated from fresh cardiac muscle by affinity chromatography contains about 1.9 mol of covalently bound phosphate/mol. Similar preparations of white-skeletal-muscle troponin I contain about 0.5 mol of phosphate/mol. 2. A 3':5'-cyclic AMP-dependent protein kinase and a protein phosphatase are associated with troponin isolated from cardiac muscle. 3. Bovine cardiac 3':5'-cyclic AMP-dependent protein kinase catalyses the phosphorylation of cardiac troponin I 30 times faster than white-skeletal-muscle troponin I. 4. Troponin I is the only component of cardiac troponin phosphorylated at a significant rate by the endogenous or a bovine cardiac 3':5'-cyclic AMP-dependent protein kinase. 5. Phosphorylase kinase catalyses the phosphorylation of cardiac troponin I at similar or slightly faster rates than white-skeletal-muscle troponin I. 6. Troponin C inhibits the phosphorylation of cardiac and skeletal troponin I catalysed by phosphorylase kinase and the phosphorylation of white skeletal troponin I catalysed by 3':5'-cyclic AMP-dependent protein kinase; the phosphorylation of cardiac troponin I catalysed by the latter enzyme is not inhibited.
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Selected References
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- BARTLETT G. R. Phosphorus assay in column chromatography. J Biol Chem. 1959 Mar;234(3):466–468. [PubMed] [Google Scholar]
- Cohen P. The subunit structure of rabbit-skeletal-muscle phosphorylase kinase, and the molecular basis of its activation reactions. Eur J Biochem. 1973 Apr 2;34(1):1–14. doi: 10.1111/j.1432-1033.1973.tb02721.x. [DOI] [PubMed] [Google Scholar]
- Ebashi S., Wakabayashi T., Ebashi F. Troponin and its components. J Biochem. 1971 Feb;69(2):441–445. doi: 10.1093/oxfordjournals.jbchem.a129486. [DOI] [PubMed] [Google Scholar]
- Elzinga M., Collins J. H., Kuehl W. M., Adelstein R. S. Complete amino-acid sequence of actin of rabbit skeletal muscle. Proc Natl Acad Sci U S A. 1973 Sep;70(9):2687–2691. doi: 10.1073/pnas.70.9.2687. [DOI] [PMC free article] [PubMed] [Google Scholar]
- England P. J. Correlation between contraction and phosphorylation of the inhibitory subunit of troponin in perfused rat heart. FEBS Lett. 1975 Jan 15;50(1):57–60. doi: 10.1016/0014-5793(75)81040-4. [DOI] [PubMed] [Google Scholar]
- Huang T. S., Bylund D. B., Stull J. T., Krebs E. G. The amino acid sequences of the phosphorylated sites in troponin-I from rabbit skeletal muscle. FEBS Lett. 1974 Jun 15;42(3):249–252. doi: 10.1016/0014-5793(74)80738-6. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Moir A. J., Wilkinson J. M., Perry S. V. The phosphorylation sites of troponin I from white skeletal muscle of the rabbit. FEBS Lett. 1974 Jun 15;42(3):253–256. doi: 10.1016/0014-5793(74)80739-8. [DOI] [PubMed] [Google Scholar]
- Panyim S., Chalkley R. High resolution acrylamide gel electrophoresis of histones. Arch Biochem Biophys. 1969 Mar;130(1):337–346. doi: 10.1016/0003-9861(69)90042-3. [DOI] [PubMed] [Google Scholar]
- Perry S. V., Cole H. A. Phosphorylation of the "37000 component" of the troponin complex (troponin-t). Biochem J. 1973 Feb;131(2):425–428. doi: 10.1042/bj1310425. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perry S. V., Cole H. A. Phosphorylation of troponin and the effects of interactions between the components of the complex. Biochem J. 1974 Sep;141(3):733–743. doi: 10.1042/bj1410733. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pratje E., Heilmeyer L. M.G. Phosphorylation of rabbit muscle troponin and actin by a 3', 5'-c-AMP-dependent protein kinase. FEBS Lett. 1972 Oct 15;27(1):89–93. doi: 10.1016/0014-5793(72)80416-2. [DOI] [PubMed] [Google Scholar]
- Reddy Y. S., Ballard D., Giri N. Y., Schwartz A. Phosphorylation of cardiac native tropomyosin and troponin: inhibitory effect of actomyosin and possible presence of endogenous myofibrillar-located cyclic-AMP-dependent protein kinase. J Mol Cell Cardiol. 1973 Oct;5(5):461–471. doi: 10.1016/0022-2828(73)90016-3. [DOI] [PubMed] [Google Scholar]
- Rubin C. S., Erlichman J., Rosen O. M. Molecular forms and subunit composition of a cyclic adenosine 3',5'-monophosphate-dependent protein kinase purified from bovine heart muscle. J Biol Chem. 1972 Jan 10;247(1):36–44. [PubMed] [Google Scholar]
- Stull J. T., Brostrom C. O., Krebs E. G. Phosphorylation of the inhibitor component of troponin by phosphorylase kinase. J Biol Chem. 1972 Aug 25;247(16):5272–5274. [PubMed] [Google Scholar]
- Syska H., Perry S. V., Trayer I. P. A new method of preparation of troponin I (inhibitory protein) using affinity chromatography. Evidence for three different forms of troponin I in striated muscle. FEBS Lett. 1974 Apr 1;40(2):253–257. doi: 10.1016/0014-5793(74)80238-3. [DOI] [PubMed] [Google Scholar]
- Tsukui R., Ebashi S. Cardiac troponin. J Biochem. 1973 May;73(5):1119–1121. doi: 10.1093/oxfordjournals.jbchem.a130168. [DOI] [PubMed] [Google Scholar]
- Weber K., Osborn M. The reliability of molecular weight determinations by dodecyl sulfate-polyacrylamide gel electrophoresis. J Biol Chem. 1969 Aug 25;244(16):4406–4412. [PubMed] [Google Scholar]