Wnt信号相关

hndxws

有没有同仁是做Wnt信号通路的，我想求助一下。对Wnt信号的描述是这样说的，有Wnt信号时，β-catenin因为不会被降解而在胞质内积累，然后进入核内调控下游基因表达，从来没见到那个地方说，是谁把β-catenin带进细胞核的，β-catenin是没有核定位序列的，有文章说的都是一些因子会对它的入核有促进和抑制作用，也有文章说它的入核可以不依赖Ran因子，从来没看到说是哪个分子负责β-catenin的入核的，难道说，它是因为胞质里浓度太高然后扩散到细胞核内的？有同仁看到过这方面文章的话，请指导一下

f5_105

同样想知道这个问题的答案，等待高人。

hndxws

难道说这方面的研究还不清楚？

生命的流浪者

β-catenin stabilization results in its higher nuclear levels, but how β-catenin is shuttled to and retained in the nucleus is not well understood Earlier studies suggested that β-catenin enters the nucleus in an NLS (nuclear localization signal)- and importin-independent fashion by interacting directly with nuclear pore proteins 。 β-atenin also exits the nucleus via export involving APC 、Axin，and RanBP3 (Ran binding protein 3), which binds to β-catenin in a Ran-GTP dependent manner . Live cell imaging suggests that while Axin and APC can enrich β-catenin in the cytoplasm and TCF and β-catenin co-activators (BCL9 and Pygopus, see below) increase
1 s4 T9 d3 n# R; ~nuclear β-catenin, they do not accelerate the export or import rate of β-catenin, thereby arguing  y( C6 J% D9 o, W0 e
for their roles in β-catenin retention rather than shuttling . Thus β-catenin nuclear and cytoplasmic partitioning is likely the dynamic sum of both shuttling and retention between the two compartments via multiple mechanisms.A recent study argues that Wnt-induced β-catenin stabilization is not sufficient for its nuclear3 M% m6 b/ I3 ^: n
accumulation, but Wnt activation of the Rac1 GTPase is required in parallel . Specifically Rac1, JNK2 (Jun N-terminal kinase 2) and β-catenin form a cytoplasmic complex, and JNK2 phosphorylates β-catenin (at serines 191 and 605) and promotes it nuclear translocation。
* S; [) |8 w1 x' \. S# E

hndxws

哦，原来这样啊，怪不得对这个地方的表述这么模糊。胞质内β-catenin积累后，别的不说，只说积累后就转移到核内。

taoqilh

在一个关于骨髓间充质干细胞的神经分化中有关于Wnt信号通路的描述，大体是Wnt信号通路通过使连环蛋白去磷酸化，让连环蛋白进入核内，和TCF家族的蛋白结合，再通过Tlx3这个转录因子调控，从而调控Wnt信号通路

高成胡君

问题好多，难受，实验没法开展