Chemical Biology and Therapeutics Science, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States.
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, United States.
J Am Chem Soc. 2020 Aug 19;142(33):14052-14057. doi: 10.1021/jacs.0c05537. Epub 2020 Aug 4.
Small molecules have been classically developed to inhibit enzyme activity; however, new classes of small molecules that endow new functions to enzymes via proximity-mediated effect are emerging. Phosphorylation (native or neo) of any given protein-of-interest can alter its structure and function, and we hypothesized that such modifications can be accomplished by small molecules that bring a kinase in proximity to the protein-of-interest. Herein, we describe phosphorylation-inducing chimeric small molecules (PHICS), which enable two example kinases-AMPK and PKC-to phosphorylate target proteins that are not otherwise substrates for these kinases. PHICS are formed by linking small-molecule binders of the kinase and the target protein, and exhibit several features of a bifunctional molecule, including the hook-effect, turnover, isoform specificity, dose and temporal control of phosphorylation, and activity dependent on proximity (i.e., linker length). Using PHICS, we were able to induce native and neo-phosphorylations of BRD4 by AMPK or PKC. Furthermore, PHICS induced a signaling-relevant phosphorylation of the target protein Bruton's tyrosine kinase in cells. We envision that PHICS-mediated native or neo-phosphorylations will find utility in basic research and medicine.
小分子一直以来都是通过抑制酶活性的方式被经典地开发出来的；然而，通过邻近效应赋予酶新功能的新型小分子正在逐渐兴起。任何给定的目标蛋白的磷酸化（天然或新）都可以改变其结构和功能，我们假设这些修饰可以通过将激酶带到目标蛋白附近的小分子来实现。在此，我们描述了磷酸化诱导的嵌合小分子（PHICS），它可以使两种激酶（AMPK 和 PKC）磷酸化原本不是这些激酶底物的靶蛋白。PHICS 是通过连接激酶和靶蛋白的小分子结合物形成的，并且表现出双功能分子的几个特征，包括钩效应、周转率、同工型特异性、磷酸化的剂量和时间控制以及邻近依赖性（即连接体长度）的活性。使用 PHICS，我们能够诱导 BRD4 被 AMPK 或 PKC 进行天然和新磷酸化。此外，PHICS 诱导了靶蛋白 Bruton 酪氨酸激酶在细胞中的信号相关磷酸化。我们设想，PHICS 介导的天然或新磷酸化将在基础研究和医学中找到应用。
