中文摘要：

为深入研究肌钙蛋白I2（TNNI2）作为核受体相互作用蛋白参与核受体基因表达调控的分子机制，采用缺失突变联合酵母双杂交技术证明了TNNI2与ERRα1的相互作用位于TNNI2的1～128位氨基酸残基区域．该区域包括TNNI2蛋白的N末端、抑制肽段（96～116位氨基酸残基）和一个核受体结合位点LXXLL模序（即NR盒）．哺乳细胞瞬时共转染实验证实，TNNI21-128缺失突变体不具备辅助活化功能，并能作为负显性突变体完全抑制野生型TNNI2的辅活化作用．研究充分证明TNNI2与核受体的相互作用定位于TNNI2蛋白1～128氨基酸残基，并从侧面进一步证实了TNNI2能辅助核受体反式激活作用的功能．

英文摘要：

The aim is to further investigate the molecular mechanism underlying the modulation effect of troponin I2 （TNNI2） on gene expression of nuclear receptors using combination of mutation and yeast twohybrid assay. The ERRα1-interacting domain on TNNI2 has been mapped to a region encompassing amino acids 1--128. This region consists of the N-terminal, inhibitory region （amino acids 96--116） and a nuclear receptor-binding site, LXXLL motif （also named NR box）. By mammalian cell transient co-transfection assays, it was demonstrated that the TNNI2 1——128 fragment lost the ability of co-transactivation function, as shown by luciferase activity, and could be acted as a dominant negative mutant to completely inhibit the wild type TNNI2 co-transactivation function. These results further supports that the TNNI2 1--128 region is the true nuclear receptor-binding domain, and confirms that TNNI2 has the co-transactivation function from another side.