National Laboratory of Protein Engineering and Plant Genetic Engineering, Peking University, Beijing, 100871, China.
Cell Mol Life Sci. 2010 Jun;67(11):1907-18. doi: 10.1007/s00018-010-0301-2. Epub 2010 Feb 26.
hCINAP is a highly conserved and ubiquitously expressed protein in eukaryotic organisms and its overexpression decreases the average number of Cajal bodies (CBs) with diverse nuclear functions. Here, we report that hCINAP is associated with important components of CBs. Depletion of hCINAP by RNA interference causes defects in CB formation and disrupts subcellular localizations of its components including coilin, survival motor neurons protein, spliceosomal small nuclear ribonucleoproteins, and nuclear protein ataxia-telangiectasia. Moreover, knockdown of hCINAP expression results in marked reduction of histone transcription, lower levels of U small nuclear RNAs (U1, U2, U4, and U5), and a loss of cell viability. Detection of increased caspase-3 activities in hCINAP-depleted cells indicate that apoptosis is one of the reasons for the loss of viability. Altogether, these data suggest that hCINAP is essential for the formation of canonical CBs, histone transcription, and cell viability.
hCINAP 是真核生物中高度保守且广泛表达的蛋白，其过表达会减少具有多种核功能的 Cajal 体（CBs）的平均数量。在这里，我们报告 hCINAP 与 CB 的重要组成部分相关联。RNA 干扰使 hCINAP 耗竭会导致 CB 形成缺陷，并破坏其包括 coilin、运动神经元生存蛋白、剪接体小核核糖核蛋白和共济失调毛细血管扩张症核蛋白在内的组成部分的亚细胞定位。此外，hCINAP 表达的敲低导致组蛋白转录显著减少，U 小核 RNA（U1、U2、U4 和 U5）水平降低，细胞活力丧失。在 hCINAP 耗竭细胞中检测到 caspase-3 活性增加表明细胞凋亡是活力丧失的原因之一。总之，这些数据表明 hCINAP 对于典型 CB 的形成、组蛋白转录和细胞活力是必需的。
