The Center For Heart Development, Hunan Normal University, Changsha, Hunan, Peoples' Republic of China.
BMB Rep. 2010 Jun;43(6):432-7. doi: 10.5483/bmbrep.2010.43.6.432.
LBH is a transcription factor as a candidate gene for CHD associated with partial trisomy 2p syndrome. To identify potential LBH-interacting partners, a yeast two-hybrid screen using LBH as a bait was performed with a human heart cDNA library. One of the clones identified encodes alphaB-crystallin. Co-immunoprecipitation and GST pull-down assays showed that LBH interacts with alphaB-crystallin, which is further confirmed by mammalian two-hybrid assays. Co-localization analysis showed that in COS-7 cells, alphaB-crystallin that is cytoplasmic alone, accumulates partialy in the nucleus when co-transfected with LBH. Transient transfection assays indicated that overexpression of LBH or alphaB-crystallin reduced the transcriptional activities of p53 and p21, respectively, Overexpression of both alphaB-crystallin and LBH together resulted in a stronger repression of the transcriptional activities of p21 and p53. These results showed that the interaction of LBH and alphaB-crystallin may inhibit synergistically the transcriptional regulation of p53 and p21.
LBH 是候选基因转录因子，与部分 2p 三体综合征相关的 CHD。为了鉴定潜在的 LBH 相互作用伙伴，使用 LBH 作为诱饵进行了酵母双杂交筛选，使用了人类心脏 cDNA 文库。鉴定出的一个克隆编码 alphaB-晶体蛋白。共免疫沉淀和 GST 下拉实验表明 LBH 与 alphaB-晶体蛋白相互作用，哺乳动物双杂交实验进一步证实了这一点。共定位分析表明，在 COS-7 细胞中，单独存在于细胞质中的 alphaB-晶体蛋白，当与 LBH 共转染时，部分积累在核内。瞬时转染实验表明，LBH 或 alphaB-晶体蛋白的过表达分别降低了 p53 和 p21 的转录活性。alphaB-晶体蛋白和 LBH 的共表达导致 p21 和 p53 的转录活性受到更强的抑制。这些结果表明，LBH 和 alphaB-晶体蛋白的相互作用可能协同抑制 p53 和 p21 的转录调节。
