Endogenous condensates with transient constituents are notoriously difficult to study with common biological assays like mass spectrometry and other proteomics profiling. Here, we report a method for light-induced targeting of endogenous condensates (LiTEC) in living cells. LiTEC combines the identification of molecular zip codes that target the endogenous condensates with optogenetics to enable controlled and reversible partitioning of an arbitrary cargo, such as enzymes commonly used in proteomics, into the condensate in a blue light-dependent manner. We demonstrate a proof of concept by combining LiTEC with proximity-based biotinylation (BioID) and uncover putative components of transcriptional condensates in mouse embryonic stem cells. Our approach opens the road to genome-wide functional studies of endogenous condensates.

中文翻译：

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光诱导靶向使内源性凝聚物的蛋白质组学成为可能


众所周知，具有瞬时成分的内源性凝聚物很难用质谱和其他蛋白质组学分析等常见生物测定法进行研究。在这里，我们报道了一种在活细胞中光诱导靶向内源性凝聚物 （LiTEC） 的方法。LiTEC 将针对内源性凝聚物的分子邮政编码的识别与光遗传学相结合，以实现任意货物（例如蛋白质组学中常用的酶）以蓝光依赖性方式受控和可逆地分配到凝聚物中。我们通过将 LiTEC 与基于邻近的生物素化 （BioID） 相结合来展示概念验证，并揭示了小鼠胚胎干细胞中转录凝聚物的推定成分。我们的方法为内源性凝聚物的全基因组功能研究开辟了道路。