过激的TLRs炎症反应是导致急性肺损伤（ALI）等疾病的重要原因。SIGIRR是TLRs信号通路中重要的负性调节蛋白，其调控机制不详。本课题组前期用酵母双杂交"钓取"并经免疫共沉淀证实Paralemmin-3（PALM3）是SIGIRR新的结合蛋白；下调PALM3表达可抑制TLR4的炎症反应，并上调细胞膜上SIGIRR的表达，推测PALM3与SIGIRR结合抑制了SIGIRR的负性调节作用。为进一步阐明其作用机制，本项目拟通过荧光共定位、基因重组等方法研究PALM3对SIGIRR细胞亚定位的影响；通过构建突变体等鉴定两蛋白的结合位点；进一步筛选与PALM3竞争结合SIGIRR的突变体蛋白，通过复制ALI小鼠模型，验证封闭PALM3与SIGIRR结合位点治疗ALI效果。本课题从分子、细胞和动物水平阐明PALM3在SIGIRR调控TLR4信号中的作用和机制，为ALI的治疗提供新的靶点和方向。

Excessive,or inappropriate activation of TLRs may lead to severe inflammation and immunity-related tissue damage, such as acute lung injury (ALI). To avoid detrimental and severe inflammatory response, single Ig IL-1R－related molecule (SIGIRR) is required for negatively regulating TLRs signaling in the immune system. However,the underlying mechanism remains unclear. Our preliminary study has verified that paralemmin-3(PALM3) is a novel binding protein of SIGIRR by a yeast two-hybrid screen and co-immunoprecipitation(Co-IP) assay. However the down-regulation of PALM3 reduced the inflammatory response in TLR4 signaling and increased the expression of SIGIRR on cell membrane.So we postulate that the combination of PALM3 and SIGIRR inhibit the role of SIGIRR in TLR4 signaling. The goal of the study is to confirm the specific interaction between PALM3 and SIGIRR by GST Pull-down assay, the role of PALM3 on dynamic changes in the subcellular distribution of SIGIRR will be detected by using confocal fluorescent microscope.Moreover, the binding site will be analyzed after co-transfection with wild or mutant of SIGIRR and PALM3 plasmids. Furthermore, the PALM3 mutants will be selected which can bind SIGIRR but not inhibit the negative effect of SIGIRR on TLR4 signal pathway.The PALM3 mutants will also be designed to intervene the process of ALI by interrupting the combination of PALM3 and SIGIRR. If successful, our results will contribute to elucidate the underlying mechanism for regulation of SIGIRR on TLRs and lead to develop the strategy to "hard to treat"inflammatory disease especially ALI.