RasTG基因在斑马鱼发育中的功能研究
文献类型：学位论文
| 作者 | 贺婧 |
| 学位类别 | 博士 |
| 答辩日期 | 2010-06-09 |
| 授予单位 | 中国科学院上海生命科学研究院营养科学研究所 |
| 授予地点 | 中国科学院上海生命科学研究院 |
| 导师 | 陈雁 |
| 关键词 | RasTG 斑马鱼 心脏瓣膜 Ras ERK信号通路 |
| 学位专业 | 生物化学与分子生物学 |
| 中文摘要 | RasTG1和RasTG2是PAQR（Progesterone and AdipoQ receptor）家族成员。PAQR家族最初为人们熟知的是PAQR1和PAQR2（即AdipoR1和AdipoR2），为脂肪细胞分泌并参与调控糖脂代谢的脂联素受体。近年的研究发现，PAQR家族成员有能够广泛地参与了MAPK信号通路的调控：PAQR1和PAQR2能够调控p38和JNK的活性；PAQR3（即RKTG）能够房室化Raf1至细胞内高尔基体并负调控下游ERK通路；我们实验室最新的前期工作发现PAQR10和PAQR11（即RasTG1和RasTG2）也能够房室化Ras到高尔基体并正调控Ras到ERK信号通路。ERK信号通路介导多种细胞生物学效应包括细胞的生长和分化，RasTGs既然参与调控如此重要的信号通路，那它们极有可能参与了胚胎的发育过程。我们利用吗啉环修饰反义寡核苷酸（Morpholino）等技术，研究了RasTG1和RasTG2在斑马鱼发育过程中的表达模式并探索了敲减RasTGs后对早期发育的影响。我们发现RasTG2在斑马鱼早期广泛表达，并在发育期心脏部位表达。RasTG2基因敲减能够导致血液在胚胎心脏中回流的表型。经过一系列组织学以及分子生物学的分析研究，我们认为RasTG2特异地影响胚胎心脏瓣膜的发育。另一方面，RasTG1在胚胎发育过程中心脏的表达量微弱，其基因敲除不导致心脏发育的异常。我们进一步分析了RasTG2参与心脏发育的分子机理，用MEK抑制剂处理胚胎以及注射显性失活形式Ras mRNA能够导致与RasTG2敲减类似的表型，而组成型激活形式的Ras则能够回复RasTG2敲减的表型。我们进一步通过利用定位于细胞内不同细胞器的Ras蛋白表达，发现只有特异定位于高尔基体上的Ras能够回复RasTG2敲减的表型。因此我们认为RasTG2调控胚胎心脏瓣膜发育是经过在高尔基体上激活Ras信号通路所介导。综上所述，通过这一研究，我们不仅发现了影响心脏瓣膜发育的新的调控分子，而且还揭示了细胞器特异激活Ras信号通路的发育生物学意义。 |
| 索取号 | D2010-061 |
| 英文摘要 | RasTG1 (PAQR10) and RasTG2 (PAQR11) belong to the PAQR (Progesterone and AdipoQ Recepoter) family. The PAQR family was first discovered when PAQR1 and PAQR2 were identified as the receptor of adiponectin, which is a hormone secreted by adipose cells and involved in the regulation of glucose and lipid matabolism. However, recent research indicated that PAQR family members may play important roles in mitogen-activated protein kinase (MAPK) signaling pathways. PAQR1 can induce activation of p38 and JNK. PAQR3 (also known as RKTG) can mobilize Raf-1 onto Golgi apparatus, thus blocking the signal transductcion from Ras to ERK. The latest research in our lab shows that PAQR10 (RasTG1) and PAQR11(RasTG1) act as spatial regulator of Ras by trapping Ras to the Golgi apparatus and induce downstream ERK signaling. Due to the discovery that RasTGs can modulate Ras signaling, we hypothesized that RasTGs might play an important role during early development. We used Morpholino strategy to knockdown RasTGs in zebrafish embryos and detected the expression of RasTGs. We found that RasTG2 were widely expressed in early embryos including heart, and RasTG2 knockdown caused blood regurgitation in embryonic heart. Through a series of histological and molecular studies we identified that RasTG2 regulates the heart valve development during zebrafish embyogenesis. In addition, expression of RasTG1 in heart is hardly detected and RasTG1 morphants developed normal heart. Moreover, embyros treated with MEK inhibitors or injected with HRasN17 (dominant negative mutant of HRas) mRNA phenocopy the RasTG2 morphants. Wildtype HRas and HRasV12 (constitutively active mutant of HRas) mRNA can rescue the heart defects caused by RasTG2 knockdown. In addition, only Golgi-localized HRas can rescue the phenotype of RasTG2 morphants while the plasma membrane-localized HRas has no effect. Thus we concluded that RasTG2 is involved in heart valve developement dependent on Ras activation in Golgi apparatus. Taken together, this study has uncovered a new regulator of valvulogenesis as well as the functional significance of compartmentalized Ras signaling in early development. |
| 语种 | 中文 |
| 源URL | [http://202.127.25.144/handle/331004/119]  |
| 专题 | 中国科学院上海生命科学研究院营养科学研究所_信号转导与营养相关疾病研究组 |
| 推荐引用方式 GB/T 7714 | 贺婧. RasTG基因在斑马鱼发育中的功能研究[D]. 中国科学院上海生命科学研究院. 中国科学院上海生命科学研究院营养科学研究所. 2010. |
入库方式： OAI收割
来源：上海营养与健康研究所
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