小G蛋白RagD对奶牛乳腺上皮细胞乳蛋白合成的影响  

Effects of small G protein RagD on milk protein synthesis in bovine mammary epithelial cells

作　　者：穆莹[1] 徐渐[1] 许岩[1] 

机构地区：[1]东北农业大学食品学院,哈尔滨150030

出　　处：《中国乳品工业》2014年第11期13-16,共4页China Dairy Industry

摘　　要：以体外培养的奶牛乳腺上皮细胞为模型,研究了RagD对细胞中β-酪蛋白(CSN2)的合成及蛋氨酸调节CSN2合成信号通路的影响。采用实时荧光定量PCR(q RT-PCR)和蛋白质免疫印迹(WB)检测添加蛋氨酸后细胞中CSN2与Rag D的表达;对Rag D进行过表达和抑制,用q RT-PCR和WB检测细胞中CSN2、mTOR和p-mTOR的表达。结果表明:添加蛋氨酸使细胞中CSN2和RagD的表达显著增加;RagD过表达时,细胞中CSN2与p-mTOR的表达显著增加,mTOR表达变化不显著,此时添加蛋氨酸,细胞中CSN2与p-m TOR的表达继续显著增加;RagD抑制时,细胞中CSN2与p-m TOR的表达显著下降,mTOR表达变化不显著(P>0.05),此时添加蛋氨酸,不能使细胞中CSN2与p-m TOR的表达恢复。RagD作为信号分子,能接收并传递蛋氨酸信号,使细胞中mTOR磷酸化,正向调节奶牛乳腺上皮细胞中CSN2的表达。The experiment was conducted to investigate the effects of RagE） on milk protein synthesis and the signaling pathway of methio- nine regulate β -casein（CSN2） synthesis in bovine mammary epithelial cells cultured in vitro. The expression of CSN2 and RagD were de- tected by real-time quantitative PCR （qRT-PCR） and western blotting （WB） in cells treated with methionine. The expression of CSN2, roTOR and p-mTOR were detected by qRT-PCR and WB in cells after RagD overexpression and inhibition. The results showed as fol- lows： the expression of CSN2 and RagD were significant increase after treated with methionine.The expression of CSN2 and p-mTOR were significant increases and significant decreases, after RagD overexpression and inhibition, but the expression of mTOR was no significant change. In RagD overexpression group, the expression of CSN2 and p-roTOR were significant increases （P〈0.01） after methioninethe was added, but in RagE） inhibition group, the expression of CSN2 and p-roTOR were no increases after methioninethe was added. The study suggests that as signaling molecules, RagE） can receive and pass methionine signal, phosphorylation the mTOR, and positively regulate the ex- pression of CSN2 in bovine mammary epithelial cells.

关 键 词：RagD 奶牛乳腺上皮细胞 Β-酪蛋白 蛋氨酸 

分 类 号：Q93-33[生物学—微生物学]