Minimal structural elements required for midline repulsive signaling and regulation of Drosophila Robo1.
Minimal structural elements required for midline repulsive signaling and regulation of Drosophila Robo1.
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DOI：
10.1371/journal.pone.0241150
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发表时间：
2020
期刊：
影响因子：
3.7
通讯作者：
Evans TA
中科院分区：
文献类型：
--
作者：
Brown HE;Evans TA
轴突导向受体的Roundabout（Robo）家族具有五个免疫球蛋白样（IG）结构域加上三个纤连蛋白III型（Fn）重复的保守胞外域排列。基于Robo受体之间这种结构域结构的强进化保守性，以及Robo家族成员的体外结构和结构域-结构域相互作用研究，预测这种胞外域排列对于响应Slit配体的Robo受体信号传导是重要的。在这里，我们定义的最小胞外域结构所需的狭缝结合和中线排斥信号在体内的果蝇Robo 1。我们发现，大多数的Robo 1胞外域的Slit结合和排斥信号。我们表明，保留了一个显着水平的中线排斥信号传导活动时，所有Robo 1胞外域元素除了Ig 1被删除，Ig 1加上一个额外的胞外域元素（Ig 2，Ig 5，或Fn 3）的组合是足以恢复中线排斥野生型水平。此外，我们发现，删除五个Robo 1 IG结构域中的四个（Δ Ig 2 -5）不会影响无Commissuerless（Comm）或Robo 2对Robo 1的负调控，而缺失所有三个纤连蛋白重复序列的变体（Δ Fn 1 -3和Δ Ig 2-Fn 3）对Comm和Robo 2的调控不敏感，这意味着Robo 1的Fn重复序列具有新的调控作用。我们的研究结果提供了一个保守的5+3胞外域结构的Robo受体的重要性在体内的角度来看，并表明，特定的生化特性和/或胞外域结构构象在体外观察到的域以外的Ig 1可能有有限的意义在体内信号的背景下中线排斥。
The Roundabout (Robo) family of axon guidance receptors has a conserved ectodomain arrangement of five immunoglobulin-like (Ig) domains plus three fibronectin type III (Fn) repeats. Based on the strong evolutionary conservation of this domain structure among Robo receptors, as well as in vitro structural and domain-domain interaction studies of Robo family members, this ectodomain arrangement is predicted to be important for Robo receptor signaling in response to Slit ligands. Here, we define the minimal ectodomain structure required for Slit binding and midline repulsive signaling in vivo by Drosophila Robo1. We find that the majority of the Robo1 ectodomain is dispensable for both Slit binding and repulsive signaling. We show that a significant level of midline repulsive signaling activity is retained when all Robo1 ectodomain elements apart from Ig1 are deleted, and that the combination of Ig1 plus one additional ectodomain element (Ig2, Ig5, or Fn3) is sufficient to restore midline repulsion to wild type levels. Further, we find that deleting four out of five Robo1 Ig domains (ΔIg2-5) does not affect negative regulation of Robo1 by Commissureless (Comm) or Robo2, while variants lacking all three fibronectin repeats (ΔFn1-3 and ΔIg2-Fn3) are insensitive to regulation by both Comm and Robo2, signifying a novel regulatory role for Robo1’s Fn repeats. Our results provide an in vivo perspective on the importance of the conserved 5+3 ectodomain structure of Robo receptors, and suggest that specific biochemical properties and/or ectodomain structural conformations observed in vitro for domains other than Ig1 may have limited significance for in vivo signaling in the context of midline repulsion.
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DOI：
10.1074/jbc.m800688200
发表时间：
2008-06-06
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Fukuhara N;Howitt JA;Hussain SA;Hohenester E
通讯作者：
Hohenester E
影响因子：
64.5
作者：
Brose, K;Bland, KS;Kidd, T
通讯作者：
Kidd, T
影响因子：
3.7
作者：
Gilestro GF
通讯作者：
Gilestro GF
影响因子：
64.5
作者：
Barak, Reut;Yom-Tov, Galit;Opatowsky, Yarden
通讯作者：
Opatowsky, Yarden
影响因子：
4.4
作者：
Huminiecki, L;Gorn, M;Bicknell, R
通讯作者：
Bicknell, R