遗传性痉挛性截瘫11型（SPG11）是AR-HSP最常见亚型，KIAA1840基因突变产生截短型spatacsin蛋白是SPG11的发病原因,但发病机制不明。在前期工作中我们发现了10种KIAA1840基因新突变。研究表明spatacsin蛋白含4个跨膜区、与线粒体和内质网共定位，在细胞处于应激状态时被磷酸化修饰,提示spatacsin蛋白很可能通过磷酸化完成其相关生理功能。本课题是在我们前期研究工作基础上，利用蛋白质质谱分析、免疫荧光共定位、免疫共沉淀、放射自显影、RNAi、电镜技术等分子生物学和蛋白质功能研究技术,鉴定spatacsin蛋白的磷酸化位点,明确spatacsin蛋白的磷酸化修饰及致病突变对spatacsin蛋白的亚细胞定位、细胞活性、细胞凋亡、氧化应激、线粒体功能及结构的影响，探讨spatacsin蛋白的磷酸化与SPG11发病机制的关系,为SPG11的治疗靶点研究奠定基础

The Spastic paraplegia 11（SPG11）is the most commonly substyle of Autosomal recessive hereditary spastic paraplegia (ARHSP). The mutations of KIAA1840 resulting in the truncated spatacsin protein were accounting for SPG11 cases, but the pathogenesis is not cleared. In the previous studies we identified 10 novel mutations in the KIAA1840 gene. Many studies have showed that spatacsin protein may contain some putative domains including four transmembrane domains, and co localized with mitochondria and endoplasmic reticulum. Spatacsin protein is modified by phosphorylation under cell stress. This suggested that phosphorylation of spatacsin may be involve in its physiologic function. This project will utilize many molecular biology and protein function methods such as mass chromatographic analysis, immunofluorescence colocalized, CO-IP, radioautography, RNAi, and electron microscopy et al. These may identify the phosphorylation sites of spatacsin protein. And to identify the change of subcellular localization of spatacsin protein, cytoactive, apoptosis, and oxidative stress, the function and structural of mitochondria when spatacsin protein is phosphorylation modified or mutated. We also try to investigate the role of phosphorylation of spatacsin protein in the pathogenesis of SPG11，and establish the groundwork for curing target point research of SPG11.