Localization of BAI‐associated protein1/membrane‐associated guanylate kinase‐1 at adherens junctions in normal rat kidney cells: Polarized targeting mediated by the carboxyl‐terminal PDZ domains
Localization of BAI‐associated protein1/membrane‐associated guanylate kinase‐1 at adherens junctions in normal rat kidney cells: Polarized targeting mediated by the carboxyl‐terminal PDZ domains
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BAI 相关蛋白 1/膜相关鸟苷酸激酶 1 在正常大鼠肾细胞粘附连接处的定位：羧基末端 PDZ 结构域介导的极化靶向
DOI：
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发表时间：
2000
影响因子：
5.6
通讯作者：
Y. Hata
中科院分区：
文献类型：
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作者：
W. Nishimura;T. Iizuka;S. Hirabayashi;N. Tanaka;Y. Hata
脑特异性血管生成抑制剂（BAI）相关蛋白（BAP）1（也称为膜相关鸟苷酸激酶[MAGI] - 1）由6个PSD‐95/Dlg‐A/ZO‐1 （PDZ）结构域、2个WW结构域和1个鸟苷酸激酶（GK）结构域组成。我们之前报道过BAP1定位于犬肾（MDCK）细胞和肠上皮细胞的紧密连接处。在这里，我们确定了BAP1在正常大鼠肾（NRK）细胞中不形成紧密连接的定位。BAP1与E‐cadherin沿外侧膜共定位，表明其定位于粘附连接处。绿色荧光蛋白（GFP）‐BAP1分布在独立的NRK细胞的胞浆中，并在NRK细胞相互接触时积聚到细胞间接触处。GFP - BAP1突变体含有第一个PDZ和GK结构域或WW和第二个PDZ结构域，定位于细胞质和细胞核中。含有第二到第四个PDZ结构域的GFP‐BAP1突变体分布在细胞质中。含有第五和第六个PDZ结构域的结构体定位于沿外侧膜的细胞-细胞接触处，少量定位于细胞核中，而缺乏第五和第六个PDZ结构域的结构体定位于细胞质和细胞核中。BAP1在体内被酪氨酸磷酸化，但酪氨酸磷酸化与BAP1的定位无关。这些结果表明，尽管BAP1的N端区域存在潜在的核定位信号，但在体内，羧基端PDZ结构域的信号主要将BAP1靶向到侧膜上。j .细胞。中国生物医学工程学报（英文版）。©2000 Wiley‐Liss, Inc。
Brain‐specific angiogenesis inhibitor (BAI)‐associated protein (BAP)1 (also called membrane‐associated guanylate kinase [MAGI]‐1) is composed of six PSD‐95/Dlg‐A/ZO‐1 (PDZ) domains, two WW domains, and one guanylate kinase (GK) domain. We previously reported that BAP1 is localized at tight junctions in Madine Darby canine kidney (MDCK) cells and intestinal epithelial cells. Here, we have determined the localization of BAP1 in normal rat kidney (NRK) cells that do not form tight junctions. BAP1 was colocalized with E‐cadherin along the lateral membrane, suggesting its localization at adherens junctions. Green fluorescent protein (GFP)‐BAP1 was distributed in the cytosol in separate NRK cells, and accumulated to the cell–cell contacts when NRK cells have contact with each other. The GFP‐BAP1 mutant containing either the first PDZ and GK domains or the WW and second PDZ domains was localized in the cytosol and the nucleus. The GFP‐BAP1 mutant containing the second to fourth PDZ domains was distributed in the cytosol. The construct containing the fifth and sixth PDZ domains was localized at the cell–cell contacts along the lateral membrane and slightly in the nucleus, whereas the construct lacking the fifth and sixth PDZ domains was localized in the cytosol and in the nucleus. BAP1 was tyrosine‐phosphorylated in vivo, but the tyrosine phosphorylation of BAP1 was not correlated with its localization. These results suggest that the signal in the carboxyl‐terminal PDZ domains functions dominantly in vivo to target BAP1 to the lateral membrane, although potential nuclear localization signals exist in the N‐terminal region of BAP1. J. Cell. Physiol. 185:358–365, 2000. © 2000 Wiley‐Liss, Inc.