Behavior of tricellulin during destruction and formation of tight junctions under various extracellular calcium conditions.
Behavior of tricellulin during destruction and formation of tight junctions under various extracellular calcium conditions.
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DOI：
10.1007/s00441-012-1512-7
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发表时间：
2013-01
影响因子：
3.6
通讯作者：
Sawada, Norimasa
中科院分区：
文献类型：
--
作者：
Takasawa, Akira;Kojima, Takashi;Ninomiya, Takafumi;Tsujiwaki, Mitsuhiro;Murata, Masaki;Tanaka, Satoshi;Sawada, Norimasa
关键词：
三纤维素蛋白是三细胞紧密连接（TJ）的重要组成部分，参与三细胞接触的形成。然而，人们对其在三细胞 TJ 组装和分解过程中的调控知之甚少。通过使用在三细胞接触处高度表达三纤维素的高分化胰腺癌细胞系HPAC，我们研究了三纤维素的定位、表达和磷酸化的变化，以及在细胞外钙浓度变化诱导的TJ破坏和形成过程中其TJ功能作为屏障和栅栏的变化。在 EGTA 处理引起的细胞外 Ca2+ 耗竭和 Ca2+ 饥饿后的 Ca2+ 补充期间，全裂解物和 Triton-X-100 不溶性级分中的 tricellulin 表达增加，而其 mRNA 没有任何变化。碱性磷酸酶处理可防止蛋白质印迹显示的免疫反应性增加。免疫沉淀分析表明，当 Ca2+ 耗尽和补充后苏氨酸残基增加时，三纤维素蛋白被磷酸化。在Ca2+补充后的早期阶段，三纤维素蛋白不仅在三细胞接触处表达，而且在细胞质和双细胞边界表达。在共聚焦激光显微镜中，在 Ca2+ 补充后，在三细胞接触的最顶端区域和基底外侧膜处观察到三纤维素蛋白。 Tricellulin 的敲低延迟了 Ca2+ 补充后屏障和栅栏功能的恢复。因此，在各种细胞外钙条件下，三纤维素纤维在 TJ 破坏和形成过程中的动态行为似乎与 TJ 的屏障和栅栏功能密切相关。本文的在线版本 (doi:10.1007/s00441-012-1512-7) 包含补充材料，可供授权用户使用。
Tricellulin is an important component of tricellular tight junctions (TJs) and is involved in the formation of tricellular contacts. However, little is known about its regulation during the assembly and disassembly of tricellular TJs. By using the well-differentiated pancreatic cancer cell line HPAC, which highly expresses tricellulin at tricellular contacts, we have investigated changes in the localization, expression and phosphorylation of tricellulin and in its TJ functions as a barrier and fence during the destruction and formation of TJs induced by changes in the extracellular calcium concentration. During both extracellular Ca2+ depletion caused by EGTA treatment and Ca2+ repletion after Ca2+ starvation, the expression of tricellulin increased in whole lysates and in Triton-X-100-insoluble fractions without any change in its mRNA. The increases in immunoreactivity revealed by Western blotting were prevented by alkaline phosphatase treatment. Immunoprecipitation assays showed that tricellulin was phosphorylated on threonine residues when it increased after Ca2+ depletion and repletion. In the early stage after Ca2+ repletion, tricellulin was expressed not only at tricellular contacts but also in the cytoplasm and at bicellular borders. In confocal laser microscopy, tricellulin was observed at the apical-most regions and basolateral membranes of tricellular contacts after Ca2+ repletion. Knockdown of tricellulin delayed the recovery of the barrier and fence functions after Ca2+ repletion. Thus, the dynamic behavior of tricellulin during the destruction and formation of TJs under various extracellular calcium conditions seems to be closely associated with the barrier and fence functions of TJs. The online version of this article (doi:10.1007/s00441-012-1512-7) contains supplementary material, which is available to authorized users.
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DOI：
10.1083/jcb.200510043
发表时间：
2005-12-19
期刊：
The Journal of cell biology
影响因子：
--
作者：
Ikenouchi J;Furuse M;Furuse K;Sasaki H;Tsukita S;Tsukita S
通讯作者：
Tsukita S
影响因子：
6.7
作者：
Kojima, Takashi;Takano, Ken-ichi;Sawada, Norimasa
通讯作者：
Sawada, Norimasa
影响因子：
--
作者：
Dörfel MJ;Huber O
通讯作者：
Huber O
通过表达突变型紧密连接膜蛋白，细胞旁通透性和跨上皮电阻的功能性分离以及顶端-基底外侧膜内扩散屏障的破坏。
影响因子：
7.8
作者：
Balda, M S;Whitney, J A;Flores, C;Gonzalez, S;Cereijido, M;Matter, K
通讯作者：
Matter, K
影响因子：
4.8
作者：
Murakami, Tomoaki;Felinski, Edward A.;Antonetti, David A.
通讯作者：
Antonetti, David A.