Functionally conservative substitutions at cardiac troponin I S43/45.
Arch Biochem Biophys
; 601: 42-7, 2016 07 01.
Article
in En
| MEDLINE
| ID: mdl-26869200
ABSTRACT
A phospho-null Ala substitution at protein kinase C (PKC)-targeted cardiac troponin I (cTnI) S43/45 reduces myocyte and cardiac contractile function. The goal of the current study was to test whether cTnIS43/45N is an alternative, functionally conservative substitution in cardiac myocytes. Partial and more extensive endogenous cTnI replacement was similar at 2 and 4 days after gene transfer, respectively, for epitope-tagged cTnI and cTnIS43/45N. This replacement did not significantly change thin filament stoichiometry. In functional studies, there were no significant changes in the amplitude and/or rates of contractile shortening and re-lengthening after this partial (2 days) and extensive (4 days) replacement with cTnIS43/45N. The cTnIS43/45N substitution also was not associated with adaptive changes in the myocyte Ca(2+) transient or in phosphorylation of the protein kinase A and C-targeted cTnIS23/24 site. These results provide evidence that cTnIS43/45N is a functionally conservative substitution, and may be appropriate for use as a phospho-null in rodent models designed for studies on PKC modulation of cardiac performance.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protein Kinase C
/
Troponin I
/
Myocytes, Cardiac
/
Myocardium
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Arch Biochem Biophys
Year:
2016
Document type:
Article
Affiliation country:
United States