The carboxyl terminus of zona occludens-3 binds and recruits a mammalian homologue of discs lost to tight junctions
The carboxyl terminus of zona occludens-3 binds and recruits a mammalian homologue of discs lost to tight junctions
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DOI：
10.1074/jbc.m201177200
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发表时间：
2002-07-26
影响因子：
4.8
通讯作者：
Margolis, B
中科院分区：
文献类型：
--
作者：
Roh, MH;Liu, CJ;Margolis, B
果蝇极性蛋白Stardust、Discs Lost和Crumbs的哺乳动物同源物已分别被鉴定为Pals 1、Pals 1相关紧密连接蛋白（PATJ）和人Crumbs同源物1（CRB 1）。我们以前已经证明，PATJ，Pals 1和CRB 1可以形成一个三方紧密连接复合体在上皮细胞和PATJ招聘Pals 1紧密连接。在这里，我们观察到Pals 1/PATJ相互作用对于PATJ本身最终靶向紧密连接并不重要。这促使我们检查是否有任何的10突触后密度-95/盘大/occludens-1（PDZ）结构域的PATJ可以结合到已知的紧密连接成分的羧基末端。我们发现PATJ的第6和第8个PDZ结构域可以分别与封闭蛋白ZO-3和claudin 1的羧基端相互作用。发现缺失第6个PDZ结构域的PATJ错误定位远离细胞接触。令人惊讶的是，删除第8个PDZ结构域对PATJ定位几乎没有影响。最后，相互免疫共沉淀实验显示全长ZO-3可以与PATJ结合。因此，PATJ/ZO-3相互作用对于将PATJ及其相关蛋白募集到紧密连接中可能是重要的。
Mammalian homologues of the Drosophila polarity proteins Stardust, Discs Lost, and Crumbs have been identified as Pals1, Pals1-associated tight junction protein (PATJ), and human Crumbs homologue 1 (CRB1), respectively. We have previously demonstrated that PATJ, Pals1, and CRB1 can form a tripartite tight junction complex in epithelial cells and that PATJ recruits Pals1 to tight junctions. Here, we observed that the Pals1/PATJ interaction was not crucial for the ultimate targeting of PATJ itself to tight junctions. This prompted us to examine if any of the 10 post-synaptic density-95/Discs Large/zona occludens-1 (PDZ) domains of PATJ could bind to the carboxyl termini of known tight junction constituents. We found that the 6(th) and 8(th) PDZ domains of PATJ can interact with the carboxyl termini of zona occludens-3 (ZO-3) and claudin 1, respectively. PATJ missing the 6(th) PDZ domain was found to mislocalize away from cell contacts. Surprisingly, deleting the 8(th) PDZ domain had little effect on PATJ localization. Finally, reciprocal co-immunoprecipitation experiments revealed that full-length ZO-3 can associate with PATJ. Hence, the PATJ/ZO-3 interaction is likely important for recruiting PATJ and its associated proteins to tight junctions.