›› 2018, Vol. 61 ›› Issue (8): 885-894.doi: 10.16380/j.kcxb.2018.08.001

• 研究论文 •    下一篇

Ras信号通路通过激活转录因子Myc促进核内复制细胞生长

张祥乐1, 马俐2,3, 马倩2, 李胜1, 刘素宁1,*   

  1. (1. 华南师范大学生命科学学院昆虫科学与技术研究所, 广州 510631; 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; 3. 上海交通大学附属儿童医院, 上海 200040)
  • 出版日期:2018-08-20 发布日期:2018-08-20

Ras signaling pathway promotes the growth of endoreplication cells through activating the expression of transcription factor Myc

ZHANG Xiang-Le1, MA Li2,3, MA Qian2, LI Sheng1, LIU Su-Ning1,*    

  1.  (1. Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China; 2. Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; 3. Children’s Hospital of Shanghai Jiaotong University, Shanghai 200040, China)
  • Online:2018-08-20 Published:2018-08-20

摘要: 【目的】果蝇Ras信号通路在细胞增殖与生长过程中发挥着重要的作用。Myc基因是bHLH转录因子家族基因,可调控细胞生长、竞争和再生增殖等生理过程。本研究旨在明确Ras信号通路与Myc的关系,探索Ras信号调控核内复制细胞生长的作用机制。【方法】生物信息学分析转基因家蚕Bombyx mori后部丝腺Myc基因的转录水平,并通过qPCR验证;在黑腹果蝇Drosophila melanogaster Kc细胞中,分别转染pAc5.1-HisB-RasV12-V5或pAc5.1-HisB-Raf-Flag过表达RasV12Raf后,通过qPCR和Western blot技术分别检测Myc基因在mRNA和蛋白水平的相对表达量;在黑腹果蝇幼虫脂肪体和唾液腺中,结合黑腹果蝇遗传工具和分子生物学手段,验证Ras信号通路对Myc基因的调控作用。【结果】家蚕后部丝腺过表达Ras1CA上调Myc转录水平。激活Ras信号使得黑腹果蝇Kc细胞内Myc在转录水平和蛋白水平上的表达量上调;黑腹果蝇幼虫唾液腺和脂肪体中,游走期Myc基因的表达量高于取食期;过表达Myc或激活Ras信号可以促进细胞核内周期进程;激活Ras信号促进Myc表达。【结论】Ras信号通路激活Myc表达,促进细胞核内周期进程,促进器官发育。

关键词: 黑腹果蝇, 家蚕, 唾液腺, 脂肪体, Ras信号通路, Myc, 核内周期

Abstract: 【Aim】 Ras signaling pathway palys an important role in cell proliferation and growth in Drosophila. Myc, a member of basic helix-loop-helix (bHLH) transcription factor family, regulates physiological processes such as cell growth, competition and tissue regeneration. The aim of this study is to clarify the interaction between Ras signaling and Myc, and to explore the mechanism how Ras signaling regulates the growth of endoreplication cells. 【Methods】 The transcription level of Myc in posterior silk glands of transgenic silkworm (Bombyx mori) was analyzed by bioinformatics tools and detected by qPCR. RasV12 or Raf wereoverexpressedby transfecting pAc5.1-HisB-RasV12-V5 or pAc5.1-HisB-Raf-Flag plasmid into Drosophila melanogaster Kc cells, respectively, and the mRNA and protein expression levels of Myc were detected by qPCR and Western blotting, respectively. The functions of Ras signaling in regulation of Myc in larval fat body and salivary glands of D. melanogaster were verified by using D. melanogaster genetic tools and molecular biology methods. 【Results】 Overexpression of Ras1CA in silkworm posterior silk glands up-regulated Myc transcriptional level. Activation of Ras signaling up-regulated Myc expression at both the transcriptional and protein levels in D. melanogaster Kc cells. In salivary glands and fat body of D. melanogaster larva, the expression levels of Myc at the wandering stage were higher than those at the feeding stage. Overexpression of Myc or activation of Ras signaling accelerated endocycling. Activating Ras signaling promoted Myc expression.【Conclusion】 The Ras signaling pathway can activate the expression of Myc, thereby accelerating the endocycle and promoting organ development.

Key words: Drosophila melanogaster, Bombyx mori, salivary gland, fat body, Ras signaling pathway, Myc, endocycle