无7蛋白氨酸激酶的信号被Ras1激活模仿
M E Fortini1, M A Simon, G M Rubin
1Howard Hughes Medical Institute, University of California, Berkeley 94720.
Nature
|February 6, 1992
概括
Ras1激活对Drosophila R7光受体的发展至关重要,它调解来自七无受体的信号. 激活Ras1拯救了R7细胞的命运,并可以诱导额外的R7细胞,显示Ras蛋白的特异性.
科学领域:
- 发育生物学是发展生物学.
- 细胞信号传递 细胞信号传递
- 遗传学 是一个遗传学.
背景情况:
- 在Drosophila中R7光受体细胞酸盐的规范是理解受体氨酸激酶信号的模型.
- 七无 (sev) 受体由七无 (boss) 结合体的新娘激活,对R7发育至关重要.
- Ras1信号传递与7介导的细胞命运决定有关.
研究的目的:
- 研究Ras1激活在Drosophila R7光受体发育过程中的七无 (Sev) 信号传递中的作用.
- 要确定Ras1激活是否足以调解Sev的所有信号功能.
- 评估Ras蛋白参与这一途径的特异性.
主要方法:
- 使用了Drosophila遗传突变物 (七号,老板零突变物).
- 在R7前体中引入激活的Ras1Va112蛋白.
- 观察Ras1激活对R7细胞命运和超数R7细胞形成的影响.
- 将Ras1激活与Ras2激活的效果进行比较.
主要成果:
- 激活的Ras1Va112在7和boss null突变体中挽救了R7前体,防止它们转化为形细胞.
- 激活的Ras1Va112诱导了超数R7细胞的形成.
- 激活Drosophila Ras2蛋白并没有产生类似的结果,这表明特异性.
结论:
- Ras1的激活足以解释七无受体的信号活动.
- Ras1在R7细胞酸盐规范途径中作用于Sev和Boss的下游.
- 这项研究强调了Ras1在调解光受体发育的诱导信号中的特定作用.
相关概念视频
The Ras Gene
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Ras is a superfamily...
Interactions Between Signaling Pathways
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Small GTPases - Ras and Rho
Ras and Rho are small monomeric GTPases that act downstream of receptor tyrosine kinase (RTK) and regulate various cellular processes. These GTPases switch between active and inactive states by binding to guanine nucleotides.
Three regulatory proteins control their activity:
Three regulatory proteins control their activity:
MAPK Signaling Cascades
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
The JAK-STAT Signaling Pathway
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
PI3K/mTOR/AKT Signaling Pathway
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a rapamycin-insensitive companion...


