Langlois-Lemay Laurence, D'Amours Damien
Ottawa Institute of Systems Biology, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
Proc Natl Acad Sci U S A. 2025 Jul 8;122(27):e2414426122. doi: 10.1073/pnas.2414426122. Epub 2025 Jul 2.
The ability of cells to overcome cell cycle arrest and adapt to the presence of unrepairable DNA damage is under the control of Polo-like kinases (PLKs) in eukaryotes. How DNA damage checkpoints are silenced or bypassed during the adaptation response is unknown, but the process requires enrichment of the Cdc5 PLK to microtubule organizing centers (MTOCs), such as the yeast centrosomes or spindle pole bodies (SPBs). Here, we found that SPBs play an active role as supramolecular organizing centers that coordinate Cdc5 recruitment and signaling to downstream effectors during the adaptation response to DNA damage. We show that SPB components Nud1, Spc110, and Spc72 are key effectors of Cdc5 recruitment to SPBs in the presence of sustained DNA damage. Following recruitment, Cdc5 transduces a phospho-signal to key structural subunits of the SPB, including Cnm67 and Mps3. We demonstrate these phosphorylation events are required to bypass cell cycle checkpoint arrest and enable effective adaptation to DNA damage. This response is specific because it cannot be recapitulated by a generic inactivation of MTOC activity. Collectively, our results indicate that centrosomes can act as supramolecular platforms to coordinate dynamic recruitment and substrate selection of PLKs during the DNA damage response (DDR).
在真核生物中，细胞克服细胞周期停滞并适应不可修复的DNA损伤的能力受Polo样激酶（PLK）的调控。在适应性反应过程中，DNA损伤检查点是如何被沉默或绕过的尚不清楚，但这一过程需要将Cdc5 PLK富集到微管组织中心（MTOC），如酵母中心体或纺锤极体（SPB）。在这里，我们发现SPB作为超分子组织中心发挥着积极作用，在对DNA损伤的适应性反应中协调Cdc5的招募及其向下游效应器的信号传导。我们表明，在持续存在DNA损伤的情况下，SPB组分Nud1、Spc110和Spc72是Cdc5招募到SPB的关键效应器。招募后，Cdc5将磷酸信号传递给SPB的关键结构亚基，包括Cnm67和Mps3。我们证明这些磷酸化事件是绕过细胞周期检查点停滞并有效适应DNA损伤所必需的。这种反应是特异性的，因为它不能通过MTOC活性的一般性失活来重现。总的来说，我们的结果表明，中心体可以作为超分子平台，在DNA损伤反应（DDR）过程中协调PLK的动态招募和底物选择。
