Analysis of regulatory mechanism for cell polarity formation by JNK binding molecules during migration

JNK/ sapk相关蛋白1（JSAP1）介导局灶黏着激酶（FAK）和JNK之间的关联，这是由Src的共表达或细胞附着于纤维连接蛋白（FN）诱导的。FAK与JSAP1和p130 crk相关底物（p130^<Cas>）的复合物形成导致FAK活性增强和JSAP1和p130^<Cas>的磷酸化，这需要p130^<Cas>的过度磷酸化，并通过抑制Src而被消除。JSAP1通过表达p130^<Cas>的显性阴性形式或抑制Src来破坏FAK/p130^<Cas>通路，从而抑制JSAP1对JNK的激活。JSAP1与JNK共定位，并在前沿磷酸化FAK，刺激细胞迁移，其迁移依赖于其JNK结合域，通过抑制JNK而受到抑制。与其他jip不同，JSAP1 mRNA水平与脑肿瘤晚期恶性程度相关。我们认为JSAP1/FAK复合体作为JNK信号通路和FN上细胞迁移的调节因子协同起作用，我们认为JSAP1也与脑肿瘤的恶性相关。MT1-MMP的表达促进了FN诱导的细胞迁移，同时伴随着FN的降解和作为肌动蛋白应激纤维锚定物的稳定局灶粘附的减少，以及整合素聚集的减弱。MT1-MMP抑制消除了整合素聚集的衰减。当在纤维连接蛋白上培养时，内源性表达MT1-MMP的HT1080细胞表现出所谓的运动形态，通过细胞迁移的痕迹，具有组织良好的局灶粘连形成，定向良好的肌动蛋白应激纤维形成和FN的裂解。抑制内源性MT1-MMP可抑制FN裂解和细胞迁移，促进稳定的局灶黏附形成，同时增强FAK酪氨酸397的磷酸化，降低ERK的激活。这些结果表明，MT1-MMP对细胞外基质的裂解促进了局灶性黏附转换和随后的ERK激活，从而刺激细胞迁移。少

JNK/SAPK-associated protein 1(JSAP1) mediated an association between focal adhesion kinase (FAK) and JNK, which was induced by either co-expression of Src or attachment of cells to fibronectin (FN). Complex formation of FAK with JSAP1 and p130 Crk-associated substrate (p130^<Cas>) resulted in augmentation of FAK activity and phosphorylation of both JSAP1 and p130^<Cas>, which required p130^<Cas> hyperphosphorylation and was abolished by inhibition of Src. JNK activation by FN was enhanced by JSAP1, which was suppressed by disrupting the FAK/p130^<Cas> pathway by expression of a dominant-negative form of p130^<Cas> or by inhibiting Src. JSAP1 was co-localized with JNK and phosphorylated FAK at the leading edge and stimulated of cell migration, which depended on its JNK binding domain and was suppressed by inhibition of JNK. The level of JSAP1 mRNA correlated with advanced malignancy in brain tumors, unlike other JIPs. We propose that the JSAP1/FAK complex functions cooperatively as a sc … More affold for the JNK signaling pathway and regulator of cell migration on FN, and we suggest that JSAP1 is also associated with malignancy in brain tumors.MT1-MMP expression promoted FN-induced cell migration, which was accompanied by FN degradation and reduction of stable focal adhesions, which function as anchors for actin-stress fibers, and attenuated integrin clustering. The attenuation of integrin clustering was abrogated by MT1-MMP inhibition. When cultured on fibronectin, HT1080 cells, which endogenously express MT1-MMP, showed so-called motile morphology with well-organized focal adhesion formation, well-oriented actin-stress fiber formation and the lysis of FN through trails of cell migration. Inhibition of endogenous MT1-MMP resulted in the suppression of FN lysis and cell migration and promotion of stable focal adhesion formation concomitant with enhanced phosphorylation of tyrosine 397 of FAK and reduced ERK activation. These results suggest that lysis of the extracellular matrix by MT1-MMP promotes focal adhesion turnover and subsequent ERK activation, which in turn stimulates cell migration. Less