细胞周期不同阶段蛋白生物功能的区分受限于缺乏不需要预处理干扰细胞周期进程的实验方法。因此，感兴趣蛋白的潜在特定周期生物功能可能受到细胞处理效应的偏倚。OsTIR1/生长素诱导降解子系统（AID）可在接触植物激素生长素后“按需”选择性和可逆地降解蛋白。在目前的格式下，这种技术无法专门地研究细胞周期中一个阶段的急性蛋白耗竭效应，因为生长素同样影响所有处理过的细胞，无论它们的增殖状态。因此，AID系统需要与细胞同步技术相结合，这可以改变所研究的细胞群体的基本生物状态，就像以前可用的方法一样。在这里，我们介绍了一种新的基于细胞周期状态调控OsTIR1水平的AID系统（ROLECCS系统），它能在细胞周期的特定阶段诱导转染的外源和内源基因敲除靶蛋白的蛋白水解作用。我们通过降低TP53蛋白水平验证了ROLECCS技术，TP53是最研究的肿瘤抑制基因之一，在细胞周期进程中有广泛的作用。通过使用我们的新工具，我们观察到TP53降解与微核数增加相关，而这个表型仅在细胞周期的S/G2/M阶段丧失TP53时才能实现，而在G1阶段则不然。因此，我们提议使用ROLECCS系统作为研究靶蛋白在细胞周期特定阶段可能发挥的不同作用的一种新的改进方式。© 2023. 作者，授予ADMC（Associazione Differenziamento e Morte Cellulare）排他许可。

The discrimination of protein biological functions in different phases of the cell cycle is limited by the lack of experimental approaches that do not require pre-treatment with compounds affecting the cell cycle progression. Therefore, potential cycle-specific biological functions of a protein of interest could be biased by the effects of cell treatments. The OsTIR1/auxin-inducible degron (AID) system allows "on demand" selective and reversible protein degradation upon exposure to the phytohormone auxin. In the current format, this technology does not allow to study the effect of acute protein depletion selectively in one phase of the cell cycle, as auxin similarly affects all the treated cells irrespectively of their proliferation status. Therefore, the AID system requires coupling with cell synchronization techniques, which can alter the basal biological status of the studied cell population, as with previously available approaches. Here, we introduce a new AID system to Regulate OsTIR1 Levels based on the Cell Cycle Status (ROLECCS system), which induces proteolysis of both exogenously transfected and endogenous gene-edited targets in specific phases of the cell cycle. We validated the ROLECCS technology by down regulating the protein levels of TP53, one of the most studied tumor suppressor genes, with a widely known role in cell cycle progression. By using our novel tool, we observed that TP53 degradation is associated with increased number of micronuclei, and this phenotype is specifically achieved when TP53 is lost in S/G2/M phases of the cell cycle, but not in G1. Therefore, we propose the use of the ROLECCS system as a new improved way of studying the differential roles that target proteins may have in specific phases of the cell cycle.© 2023. The Author(s), under exclusive licence to ADMC Associazione Differenziamento e Morte Cellulare.