Laboratory of Applied Mechanobiology, Institute of Translational Medicine, Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland.
PLoS One. 2019 Jul 10;14(7):e0218893. doi: 10.1371/journal.pone.0218893. eCollection 2019.
A large number of extracellular matrix proteins have been found in phosphorylated states, yet little is known about how the phosphorylation of extracellular matrix proteins might affect cell functions. We thus tested the hypothesis whether the phosphorylation of fibronectin, a major adhesion protein, affects cell behavior. Controlled in vitro phosphorylation of fibronectin by a casein kinase II (CKII) significantly upregulated cell traction forces and total strain energy generated by fibroblasts on nanopillar arrays, and consequently other elementary cell functions including cell spreading and metabolic activity. Mass spectrometry of plasma fibronectin from healthy human donors then identified a constitutively phosphorylated site in the C-terminus, and numerous other residues that became phosphorylated by the CKII kinase in vitro. Our findings open up novel strategies for translational applications including targeting diseased ECM, or to develop assays that probe the phosphorylation state of the ECM or blood as potential cancer markers.
大量细胞外基质蛋白被发现处于磷酸化状态，但对于细胞外基质蛋白的磷酸化如何影响细胞功能知之甚少。因此，我们测试了假设，即主要黏附蛋白纤维连接蛋白的磷酸化是否会影响细胞行为。通过酪蛋白激酶 II（CKII）在体外对纤维连接蛋白进行受控磷酸化，显著上调了成纤维细胞在纳米柱阵列上产生的细胞牵引力和总应变能，从而也影响了包括细胞铺展和代谢活性在内的其他基本细胞功能。然后，对来自健康人类供体的血浆纤维连接蛋白进行质谱分析，鉴定出 C 末端的一个固有磷酸化位点，以及体外 CKII 激酶磷酸化的许多其他残基。我们的发现为转化应用开辟了新的策略，包括针对病变细胞外基质，或开发探测细胞外基质或血液磷酸化状态的测定方法作为潜在的癌症标志物。
