Plakophilin 1 but not plakophilin 3 regulates desmoglein clustering
Plakophilin 1 but not plakophilin 3 regulates desmoglein clustering
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DOI：
10.1007/s00018-019-03083-8
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发表时间：
2019-09-01
影响因子：
8
通讯作者：
Vielmuth, Franziska
中科院分区：
文献类型：
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作者：
Fuchs, Michael;Foresti, Marco;Vielmuth, Franziska
原核亲和素(PKP)是桥粒黏附的关键蛋白，参与桥粒周转和信号转导的调节。然而，缺乏直接证据表明Pkps调控桥粒钙粘附素的聚集和分子结合特性。在这里，与野生型角质形成细胞相比，缺少Pkp1或3的角质形成细胞的特征在于它们与桥粒芯糖蛋白(Dsg)1和3结合的特性以及它们诱导Dsg3聚集的能力。原子力显微镜(AFM)显示，两种PKP缺陷型角质形成细胞系的细胞膜利用率和DSG1和DSG3在细胞边界的结合频率均降低。胞外交联和AFM聚类图表明，Dsg3聚类所需要的是Pkp1而不是Pkp3。因此，AFM和STED实验表明，Dsg3过表达可在Pkp3缺失的角质形成细胞中形成重组簇，而不是Pkp1缺失的角质形成细胞。综上所述，这些数据表明，Pkp1和3都调节DSG膜的利用率，而Dsg3聚类需要Pkp1而不是Pkp3。
Plakophilins (Pkp) are desmosomal plaque proteins crucial for desmosomal adhesion and participate in the regulation of desmosomal turnover and signaling. However, direct evidence that Pkps regulate clustering and molecular binding properties of desmosomal cadherins is missing. Here, keratinocytes lacking either Pkp1 or 3 in comparison to wild type (wt) keratinocytes were characterized with regard to their desmoglein (Dsg) 1- and 3-binding properties and their capability to induce Dsg3 clustering. As revealed by atomic force microscopy (AFM), both Pkp-deficient keratinocyte cell lines showed reduced membrane availability and binding frequency of Dsg1 and 3 at cell borders. Extracellular crosslinking and AFM cluster mapping demonstrated that Pkp1 but not Pkp3 is required for Dsg3 clustering. Accordingly, Dsg3 overexpression reconstituted cluster formation in Pkp3- but not Pkp1-deficient keratinocytes as shown by AFM and STED experiments. Taken together, these data demonstrate that both Pkp1 and 3 regulate Dsg membrane availability, whereas Pkp1 but not Pkp3 is required for Dsg3 clustering.