A regulated complex of the scaffolding proteins PDZK1 and EBP50 with ezrin contribute to microvillar organization.
A regulated complex of the scaffolding proteins PDZK1 and EBP50 with ezrin contribute to microvillar organization.
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DOI：
10.1091/mbc.e10-01-0008
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发表时间：
2010-05-01
影响因子：
3.3
通讯作者：
Bretscher A
中科院分区：
文献类型：
--
作者：
LaLonde DP;Garbett D;Bretscher A
我们表征了PDZK 1，EBP 50和ezrin的三元复合物，该三元复合物受其个体分子间和分子内相互作用的调节。PDZK 1被证明经历细胞融合依赖性核质穿梭，调节该复合物的形成。显示了PDZK 1和EBP 50在微绒毛维持中的功能冗余。PDZK 1和ezrin，radixin，moesin结合磷蛋白50 kDa（EBP 50）是在极化上皮细胞的顶端微绒毛中发现的含有突触后密度95/盘大/盘闭塞（PDZ）结构域的支架蛋白。二元相互作用已被证明之间的尾部PDZK 1和EBP 50的PDZ结构域，以及EBP 50和膜细胞骨架连接蛋白埃兹蛋白。在这里，我们表明，这些分子在体外和体内形成一个受调节的三元复合物。复合物的形成是合作的，因为ezrin积极影响PDZK 1/EBP 50相互作用。此外，EBP 50的相邻PDZ结构域的占用增强了PDZK 1与EBP 50的相互作用。该复合物还受位置的调节，因为PDZK 1从低汇合细胞的细胞核穿梭到高汇合细胞的微绒毛，这在体内调节PDZK 1/EBP 50/ezrin复合物的形成。EBP 50的敲低减少了微绒毛的存在，微绒毛是一种可以通过EBP 50再表达或直接靶向埃兹蛋白的PDZK 1嵌合体的表达来挽救的表型。因此，当适当定位时，PDZK 1可以提供通常由EBP 50提供的微绒毛形成所必需的功能。通过进入三元复合物，PDZK 1可以增强顶膜处的支架以及增强EBP 50在微绒毛形成中的作用。
We characterize a ternary complex of PDZK1, EBP50, and ezrin that is regulated by their individual inter- and intramolecular interactions. PDZK1 is shown to undergo cell confluence-dependent nucleocytoplasmic shuttling that regulates the formation of this complex. A functional redundancy between PDZK1 and EBP50 in microvilli maintenance is shown. PDZK1 and ezrin, radixin, moesin binding phosphoprotein 50 kDa (EBP50) are postsynaptic density 95/disc-large/zona occludens (PDZ)-domain–containing scaffolding proteins found in the apical microvilli of polarized epithelial cells. Binary interactions have been shown between the tail of PDZK1 and the PDZ domains of EBP50, as well as between EBP50 and the membrane–cytoskeletal linking protein ezrin. Here, we show that these molecules form a regulated ternary complex in vitro and in vivo. Complex formation is cooperative because ezrin positively influences the PDZK1/EBP50 interaction. Moreover, the interaction of PDZK1 with EBP50 is enhanced by the occupancy of EBP50's adjacent PDZ domain. The complex is further regulated by location, because PDZK1 shuttles from the nucleus in low confluence cells to microvilli in high confluence cells, and this regulates the formation of the PDZK1/EBP50/ezrin complex in vivo. Knockdown of EBP50 decreases the presence of microvilli, a phenotype that can be rescued by EBP50 re-expression or expression of a PDZK1 chimera that is directly targeted to ezrin. Thus, when appropriately located, PDZK1 can provide a function necessary for microvilli formation normally provided by EBP50. By entering into the ternary complex, PDZK1 can both enhance the scaffolding at the apical membrane as well as augment EBP50's role in microvilli formation.
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DOI：
10.1083/jcb.200604046
发表时间：
2006-12-04
期刊：
The Journal of cell biology
影响因子：
--
作者：
Hanono A;Garbett D;Reczek D;Chambers DN;Bretscher A
通讯作者：
Bretscher A
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10.1083/jcb.200801047
发表时间：
2008-05-05
期刊：
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影响因子：
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影响因子：
7.8
作者：
Fievet, BT;Gautreau, A;Roy, C;Del Maestro, L;Mangeat, P;Louvard, D;Arpin, M
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影响因子：
4.8
作者：
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影响因子：
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Saotome, I;Curto, M;McClatchey, AI
通讯作者：
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