Identification of cis-acting DNA elements required for expression of the human cardiac troponin I gene promoter

J Mol Cell Cardiol. 2000 Jan;32(1):95-108. doi: 10.1006/jmcc.1999.1058.


The human cardiac troponin I (TnIc) gene exhibits both cardiac-specific and developmentally regulated expression. The structure and expression of this gene as well as the identification of putative regulatory elements have been described previously. This study shows that a minimal promoter containing 98 bp of sequence is sufficient to drive transcription in neonatal rat cardiac myocytes. This region contains several putative cis -regulatory elements including an Initiator element surrounding the start site of transcription, an A/T-rich (TATA/MEF-2) element, two GATA elements and a cytosine-rich region containing overlapping CACC box and Sp1 elements. Using electrophoretic mobility shift assays (EMSAs) this study demonstrates the binding of MEF-2, Oct-1, and recombinant TBP to the A/T-rich element and of GATA-4 to both GATA elements. The CACC/Sp element binds the zinc finger transcription factors Sp1 and Sp3 in addition to an unidentified complex present in neonatal rat cardiac myocytes. Mutation of each of these sites has a deleterious effect on promoter activity as assayed by transient transfection into cardiac myocytes. The data suggest that transcriptional activity of the human TnIc gene can be driven by a compact promoter region and that within this region GATA, MEF-2 Sp1 and CACC box-binding factors are required for optimal activity. Furthermore, a comparison with data obtained for identical elements in the promoters of rodent TnIc genes identifies differences between species which may be of consequence for species-specific promoter function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites
  • Cells, Cultured
  • Cytosine
  • Gene Expression Regulation*
  • Humans
  • Mice
  • Molecular Sequence Data
  • Myocardium / cytology
  • Myocardium / metabolism*
  • Promoter Regions, Genetic*
  • Rats
  • Rats, Sprague-Dawley
  • Sequence Homology, Nucleic Acid
  • Transcription, Genetic
  • Troponin I / genetics*


  • Troponin I
  • Cytosine