转录辅助因子CrEDF1调控纤毛长度平衡的分子机理

细胞怎样调控自身细胞器的大小是细胞生物学中一个重要的未解难题。真核生物纤毛或鞭毛是研究细胞器大小调控的理想模型，主要是由于纤毛的大小可由长度衡量。通过大规模突变体筛选得到衣藻纤毛长度不等长突变体edf1。研究表明纤毛组装过程中CrEDF1表达增加，CrEDF1蛋白进入纤毛依赖于纤毛内运输机制。CrEDF1也存在于细胞核中并以转录辅助因子的形式参与纤毛基因转录。研究还发现纤毛长度调控复合物LRC影响CrEDF1在纤毛和细胞核中的定位。拟进一步研究细胞周期过程中CrEDF1的表达，CrEDF1在纤毛和细胞核中的运输以及LRC调控CrEDF1定位等的分子机制。深入研究单细胞水平CrEDF1在纤毛长度平衡中的作用机制，及其靶基因调控纤毛组装和解聚的分子机理。研究CrEDF1调控纤毛长度平衡的作用机制，将有助于发现和理解其他细胞器大小调控的作用机理，从而促进细胞器大小控制研究领域的发展。

An important unanswered question in cell biology is how cells control the size of their organelles. Eukaryotic cilium or flagellum is an ideal model system to investigate the mechanism of organelle size control, mainly because the organelle maintains a constant diameter as it assembles and disassembles, thus making it essentially a one-dimensional organelle and its size can be determined simply by measuring its length. In the previous study, we obtained a distinct unequal-length cilia mutant edf1, by using large-scale insertional mutagenesis in Chlamydomonas which is a model organism for studies of cilia. Our results showed that the expression of CrEDF1 was up-regulated by deflagellation, and the transport of CrEDF1 into cilia during ciliary assembly depended on IFT. However, CrEDF1 also existed in the nucleus and regulated the transcription of cilia-associated genes as a transcriptional activator. In addition, the ciliary and nuclear localization of the CrEDF1 protein were lost when genes that made up the proteins in the cytoplasmic length regulatory complex (LRC) were mutated. Hence, our study aimed to further investigate the regulatory mechanisms of CrEDF1 expression during cell cycle, CrEDF1 transport in cilia and nuclei, and the LRC regulating the localization of CrEDF1. We intend to further study the mechanism by which CrEDF1 is participated in ciliary length equalization in single cells, and unravel the molecular mechanisms of CrEDF1 target genes involved in ciliary assembly and disassembly. The study on the molecular mechanism of transcriptional coactivator CrEDF1 in regulating ciliary length equalization will facilitate the discovery and.understanding of the mechanisms of other complex organelle size regulation, thus promoting the development of the field of organelle size control.