Townsend P J, Farza H, MacGeoch C, Spurr N K, Wade R, Gahlmann R, Yacoub M H, Barton P J
Department of Cardiothoracic Surgery, National Heart and Lung Institute, London, United Kingdom.
Genomics. 1994 May 15;21(2):311-6. doi: 10.1006/geno.1994.1271.
The troponin complex is located on the thin filament of striated muscle and is composed of three component polypeptides: troponin T, troponin I, and troponin C. Three troponin T genes have been described on the basis of molecular cloning in humans and other vertebrates. These are expressed in a tissue-specific manner and encode the troponin T isoforms expressed in cardiac muscle, slow skeletal muscle, and fast skeletal muscle, respectively. Each of these genes is subject to alternative splicing, resulting in the production of multiple tissue-specific isoforms. We have cloned cDNAs encoding human cardiac troponin T from adult heart and have used these to demonstrate that multiple cardiac troponin T mRNAs are present in the human fetal heart, resulting from alternative splicing in the 5' coding region of the gene. Hybridization of the cloned cDNAs to genomic DNA identifies a single-copy gene, and using somatic cell hybrid analysis, we have mapped the corresponding gene locus (designated TNNT2) to the long arm of chromosome 1 (1cen-qter).
肌钙蛋白复合体位于横纹肌的细肌丝上，由三种组成多肽构成：肌钙蛋白T、肌钙蛋白I和肌钙蛋白C。基于在人类和其他脊椎动物中的分子克隆，已描述了三个肌钙蛋白T基因。这些基因以组织特异性方式表达，分别编码在心肌、慢骨骼肌和快骨骼肌中表达的肌钙蛋白T同工型。这些基因中的每一个都经历可变剪接，导致产生多种组织特异性同工型。我们已从成人心脏中克隆了编码人心脏肌钙蛋白T的cDNA，并利用这些cDNA证明人胎儿心脏中存在多种心脏肌钙蛋白T mRNA，这是由该基因5'编码区的可变剪接产生的。克隆的cDNA与基因组DNA杂交可鉴定出一个单拷贝基因，并且通过体细胞杂交分析，我们已将相应的基因座（命名为TNNT2）定位到染色体1的长臂（1cen-qter）上。
