PI3K/AKT/TORC1信号通路对丝素蛋白合成转录因子SGF1表达的影响  

Impact of Signaling Pathway PI3K/AKT/TORC1 on Expression of Transcription Factor SGF1 Involved in Bombyx mori Fibroin Pro-tein Synthesis

作　　者：郭亚新[1,2] 马俐[2] 李胜[2] 李恺[1] 

机构地区：[1]华东师范大学生命科学学院,上海200241 [2]中国科学院上海生命科学研究院植物生理生态研究所,上海200032

出　　处：《蚕业科学》2017年第2期231-237,共7页ACTA SERICOLOGICA SINICA

基　　金：国家重大基础研究计划"973"项目(No.2012CB114605)

摘　　要：SGF1(silk gland factor 1)是一种转录调控因子,属于Fox家族的Fox A亚家族成员,能够启动丝素基因的表达,合成丝素蛋白。已知果蝇和其他高等动物中的PI3K/AKT/TORC1信号通路可以调控Fox转录蛋白的表达。为了探究家蚕幼虫后部丝腺(PSG)中PI3K/AKT/TORC1信号通路对SGF1表达水平的影响,对4龄第4天和5龄第7天家蚕幼虫分别注射信号通路抑制剂Wort、Rapa和LY294,24 h后解剖取出后部丝腺,一组用于免疫组织化学染色实验,另一组用于提取蛋白质进行Western blot检测。免疫组织化学染色实验表明,与对照组相比,注射3种信号通路抑制剂的家蚕幼虫后部丝腺组织的绿色荧光亮度明显减弱;Western blot检测表明,与对照组相比,实验组家蚕幼虫后部丝腺的蛋白质浓度有所下降。综合以上结果初步得出PI3K/AKT/TORC1信号通路抑制剂处理均可降低家蚕幼虫后部丝腺中SGF1表达的结论,即提示可以通过上游信号通路PI3K/AKT/TORC1影响SGF1的表达水平,进而调控丝素蛋白的合成。Silk gland factor 1 （SGF1） is a fork head box （Fox） family transcription factor belonging to FoxA subgroup. SGF1 can start up the expression of fibroin genes in silkworm （ Bombyx mori） to synthesize fibroin proteins. Controlling of Fox protein expression through PI3K/AKT/TORC1 signaling pathway has already been reported in Drosophila and other higher animals. To elucidate the effect of signaling pathway PI3K/AKT/TORC1 in the posterior silk gland （PSG） of silk- worm on the expressional level of SGF1, PI3K/AKT/TORC1 signaling specific inhibitors Wort, Rapa and LY294 were in- jected into day 4 silkworm larvae of the 4th instar and day 7 silkworm larvae of the 5th instar, respectively. At 24 h after in- jection, PSGs were dissected for immunohistochemistry staining and Western blotting to detect the change of SGF1 ex- pression. The immunohistochemistry staining results indicated that fluorescent brightness of SGF1 in inhibitor-treated groups was obviously weakened when compared with control group. Western blot results also showed that, compared with control group, protein concentrations in inhibitor-treated groups were decreased slightly. Based on these data, it is concluded that SGF1 protein expres- sion can be down-regulated by PI3K/AKT/TORCl signa- ling pathway inhibitor and then decrease the expression of fibroin proteins in PSG of silkworm.

关 键 词：家蚕丝素蛋白 表达调控 SGF1因子 PI3K/AKT/TORC1信号通路 免疫组织化学染色 免疫印迹法 

分 类 号：S881.2[农业科学—特种经济动物饲养] Q786[农业科学—畜牧兽医]