Large-scale Discovery of Substrates of the Human Kinome (NEK1) [Reanalysis: JPST000508]

Kinase -networks are important for cellular signal transduction. Despite tremendous efforts to uncover these signaling pathways, huge numbers of uncharacterized phosphosites still remain in the human proteome. Because of the transient nature of kinase-substrate interactions in vivo, it is almost impossible to identify direct substrates. Here, we present a novel strategy for the rapid and high-throughput discovery for of kinase substrates of kinase using quantitative proteomics. Using 385 purified kinases, we identified a total of 175,574 potential direct kinase substrates of kinases. In addition, we identified novel kinase groups, such as one group containing 30 threonine-directed kinases and another containing 15 serine/threonine/tyrosine kinase sgroup. Surprisingly, we observed that the diversity of substrates for tyrosine kinases was much higher than that for serine-threonine kinases. [Original project description]

激酶（kinase）网络对于细胞信号转导至关重要。尽管学界已付出巨大努力来解析这些信号通路，但人类蛋白质组中仍存在大量未被表征的磷酸化位点（phosphosites）。由于体内激酶-底物相互作用（kinase-substrate interactions）具有瞬时特性，直接鉴定其直接底物几乎不可能。在此，我们提出一种基于定量蛋白质组学（quantitative proteomics）的全新策略，可实现激酶底物的快速高通量发现。我们利用385种纯化的激酶，共鉴定得到175574个潜在的激酶直接底物。此外，我们还鉴定出了新的激酶类群：例如包含30种苏氨酸靶向激酶的类群，以及包含15种丝氨酸/苏氨酸/酪氨酸激酶（serine/threonine/tyrosine kinase）的类群。令人意外的是，我们观察到酪氨酸激酶的底物多样性远高于丝氨酸-苏氨酸激酶。[原始项目描述]