PLAKOGLOBIN - KINETICS OF SYNTHESIS, PHOSPHORYLATION, STABILITY, AND INTERACTIONS WITH DESMOGLEIN AND E-CADHERIN
PLAKOGLOBIN - KINETICS OF SYNTHESIS, PHOSPHORYLATION, STABILITY, AND INTERACTIONS WITH DESMOGLEIN AND E-CADHERIN
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DOI：
10.1002/cm.970320403
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发表时间：
1995-01-01
影响因子：
--
通讯作者：
CHLUMECKY, V
中科院分区：
文献类型：
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作者：
PASDAR, M;LI, Z;CHLUMECKY, V
我们已经分析了动力学的合成，磷酸化，和稳定性的可溶性和不溶性斑珠蛋白（PG）和它们的相互作用与Dsg 1和E-钙粘蛋白在Madin-Darby犬肾（MDCK）上皮细胞中的细胞粘附的情况下，诱导细胞-细胞接触后。使用生物化学和形态学的方法相结合，我们表明，新合成的PG进入一个可溶性的：不溶性的蛋白质池在60：40的比例，无论细胞-细胞接触。合成后，PG越来越多地发现在不溶性池。虽然细胞-细胞接触不影响每个池的大小或从可溶性转移到不溶性池的速率或效率，但它导致新合成的不溶性PG的代谢稳定性显着增加。可溶性PG最初与E-钙粘蛋白和Dsg 1形成单独的复合物。PG-Dsg 1复合物变得不溶并定位于桥粒。PG-E-钙粘蛋白复合物保持可溶性并分布在细胞内。在细胞外周检测到的不溶性PG和E-钙粘蛋白保持明显分离，如先前所证明的[Hinck等人，1994：J. Cell Biol.125：1327-1340; Nathke等人，125：1341-1352]。此外，我们检测到一个单独的PG池，它不与Dsg 1或E-钙粘蛋白，并在诱导细胞-细胞接触后变得主要不溶，并分布沿着侧膜。磷酸化分析显示，可溶性池中磷酸化PG的量显著大于不溶性池中的磷酸化PG的量。此外，可溶性池是丝氨酸和苏氨酸磷酸化的，而不溶性PG主要是丝氨酸残基磷酸化。(C)1995 Wiley-Liss，Inc.
We have analyzed the kinetics of synthesis, phosphorylation, and stability of the soluble and insoluble plakoglobin (PG) and their interactions with Dsg1 and E-cadherin in Madin-Darby canine kidney (MDCK) epithelial cells in the absence of cell adhesion and after the induction of cell-cell contact. Using a combination of biochemical and morphological approaches, we show that newly synthesized PG enters a soluble:insoluble pool of proteins in a 60:40 ratio regardless of cell-cell contact. Following synthesis, PG is increasingly found in the insoluble pool. Although cell-cell contact does not effect either the size of each pool or the rate or efficiency of the transfer from the soluble into the insoluble pool, it results in a significant increase in the metabolic stability of the newly synthesized insoluble PG. The soluble PG initially forms separate complexes with E-cadherin and Dsg1. PG-Dsg1 complexes become insoluble and localize to the desmosome. PG-E-cadherin complexes remain soluble and are distributed intracellularly. The insoluble PG and E-cadherin detected at the cell periphery remain distinctly separate, as demonstrated previously [Hinck et al., 1994: J. Cell Biol. 125:1327-1340; Nathke et al., 1994: J. Cell Biol. 125:1341-1352]. In addition, we detected a separate pool of PG which is not associated with either Dsg1 or E-cadherin and after the induction of cell-cell contact becomes primarily insoluble and is distributed along the lateral membrane. Phosphorylation analysis showed that there is a significantly greater amount of phosphorylated PG in the soluble pool than in the insoluble pool. In addition the soluble pool is both serine and threonine phosphorylated, whereas the insoluble PG is primarily phosphorylated on serine residues. (C) 1995 Wiley-Liss, Inc.