HGNC Approved Gene Symbol: TNNI1
Cytogenetic location: 1q32.1 Genomic coordinates (GRCh38): 1:201,403,784-201,421,730 (from NCBI)
The Ca(2+)-based regulation of striated muscle contraction is mediated by the troponin complex. This complex comprises 3 closely associated proteins: troponin T (see 191041), troponin C (see 191040), and troponin I. The troponin subunit genes appear to be coordinately activated during skeletal muscle development. The proteins of the troponin complex belong to separate multigene families whose members are expressed in a muscle fiber-type-specific manner. The troponin I gene family comprises 3 isoforms: 2 skeletal muscle isoforms, TnI-fast (191043) and TnI-slow, and a cardiac isoform, TnI-cardiac (191044) (summary by Wade et al., 1990).
Wade et al. (1990) isolated a full-length cDNA representing the human slow-twitch skeletal muscle isoform of troponin I (TNNI1). Sequence comparisons showed that the protein is highly conserved between species.
By use of a human-specific probe prepared from the 3-prime untranslated region of the TNNI1 cDNA to probe a panel of human/mouse somatic cell hybrid lines, Wade et al. (1990) mapped the gene to chromosome 1q12-qter. Using PCR of radiation hybrids, Tiso et al. (1997) mapped the TNNI1 gene to 1q31.3, within 1 Mb of cardiac troponin-T (TNNT2; 191045).
Guenet et al. (1996) demonstrated that the Tnni1 gene is located on mouse chromosome 1 in a region of homology to human 1q.
Guenet, J.-L., Simon-Chazottes, D., Gravel, M., Hastings, K. E. M., Schiaffino, S. Cardiac and skeletal muscle troponin I isoforms are encoded by a dispersed gene family on mouse chromosomes 1 and 7. Mammalian Genome 7: 13-15, 1996. [PubMed: 8903721] [Full Text: https://doi.org/10.1007/s003359900004]
Tiso, N., Rampoldi, L., Pallavicini, A., Zimbello, R., Pandolfo, D., Valle, G., Lanfranchi, G., Danieli, G. A. Fine mapping of five human skeletal muscle genes: alpha-tropomyosin, beta-tropomyosin, troponin-I slow-twitch, troponin-I fast-twitch, and troponin-C fast. Biochem. Biophys. Res. Commun. 230: 347-350, 1997. [PubMed: 9016781] [Full Text: https://doi.org/10.1006/bbrc.1996.5958]
Wade, R., Eddy, R., Shows, T. B., Kedes, L. cDNA sequence, tissue-specific expression, and chromosomal mapping of the human slow-twitch skeletal muscle isoform of troponin I. Genomics 7: 346-357, 1990. [PubMed: 2365354] [Full Text: https://doi.org/10.1016/0888-7543(90)90168-t]