Reversible compartmentalization of de novo purine biosynthetic complexes in living cells
Reversible compartmentalization of de novo purine biosynthetic complexes in living cells
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DOI：
10.1126/science.1152241
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发表时间：
2008-04-04
期刊：
影响因子：
56.9
通讯作者：
Benkovic, Stephen J.
中科院分区：
文献类型：
--
作者：
An, Songon;Kumar, Ravindra;Benkovic, Stephen J.
嘌呤是通过 10 个化学步骤从头合成的，这些步骤由真核生物中的 6 种酶催化。体外研究几乎没有提供预期的蛋白质-蛋白质相互作用的证据，这种相互作用将实现底物通道和代谢通量的调节。我们将荧光显微镜应用于 HeLa 细胞，发现所有六种酶在细胞质中共定位形成簇。通过改变培养基的嘌呤水平或向培养基中添加外源性试剂，可以动态调节这些酶簇的结合和解离。总的来说，这些数据为多酶复合物“嘌呤体”的形成提供了强有力的证据，以在细胞中进行从头嘌呤生物合成。
Purines are synthesized de novo in 10 chemical steps that are catalyzed by six enzymes in eukaryotes. Studies in vitro have provided little evidence of anticipated protein- protein interactions that would enable substrate channeling and regulation of the metabolic flux. We applied fluorescence microscopy to HeLa cells and discovered that all six enzymes colocalize to form clusters in the cellular cytoplasm. The association and dissociation of these enzyme clusters can be regulated dynamically, by either changing the purine levels of or adding exogenous agents to the culture media. Collectively, the data provide strong evidence for the formation of a multi- enzyme complex, the "purinosome," to carry out de novo purine biosynthesis in cells.