Apical targeting of syntaxin 3 is essential for epithelial cell polarity.
Apical targeting of syntaxin 3 is essential for epithelial cell polarity.
复制标题
语法素3的顶靶靶向对于上皮细胞极性至关重要。
DOI：
10.1083/jcb.200603132
复制
发表时间：
2006-06-19
影响因子：
7.8
通讯作者：
Weimbs, Thomas
中科院分区：
文献类型：
--
作者：
Sharma, Nikunj;Low, Seng Hui;Misra, Saurav;Pallavi, Bhattaram;Weimbs, Thomas
In polarized epithelial cells, syntaxin 3 localizes to the apical plasma membrane and is involved in membrane fusion of apical trafficking pathways. We show that syntaxin 3 contains a necessary and sufficient apical targeting signal centered around a conserved FMDE motif. Mutation of any of three critical residues within this motif leads to loss of specific apical targeting. Modeling based on the known structure of syntaxin 1 revealed that these residues are exposed on the surface of a three-helix bundle. Syntaxin 3 targeting does not require binding to Munc18b. Instead, syntaxin 3 recruits Munc18b to the plasma membrane. Expression of mislocalized mutant syntaxin 3 in Madin-Darby canine kidney cells leads to basolateral mistargeting of apical membrane proteins, disturbance of tight junction formation, and loss of ability to form an organized polarized epithelium. These results indicate that SNARE proteins contribute to the overall specificity of membrane trafficking in vivo, and that the polarity of syntaxin 3 is essential for epithelial cell polarization.
