MTA SZBK Lendület Laboratory of Cell Cycle Regulation, Institute of Biochemistry, HUN-REN Biological Research Centre, H-6726 Szeged, Hungary.
Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary.
Cells. 2023 Sep 6;12(18):2219. doi: 10.3390/cells12182219.
Genome stability in human cells relies on the efficient repair of double-stranded DNA breaks, which is mainly achieved by homologous recombination (HR). Among the regulators of various cellular functions, Protein phosphatase 4 (PP4) plays a pivotal role in coordinating cellular response to DNA damage. Meanwhile, Centrobin (CNTRB), initially recognized for its association with centrosomal function and microtubule dynamics, has sparked interest due to its potential contribution to DNA repair processes. In this study, we investigate the involvement of PP4 and its interaction with CNTRB in HR-mediated DNA repair in human cells. Employing a range of experimental strategies, we investigate the physical interaction between PP4 and CNTRB and shed light on the importance of two specific motifs in CNTRB, the PP4-binding FRVP and the ATR kinase recognition SQ sequences, in the DNA repair process. Moreover, we examine cells depleted of PP4 or CNTRB and cells harboring FRVP and SQ mutations in CNTRB, which result in similar abnormal chromosome morphologies. This phenomenon likely results from the impaired resolution of Holliday junctions, which serve as crucial intermediates in HR. Taken together, our results provide new insights into the intricate mechanisms of PP4 and CNTRB-regulated HR repair and their interrelation.
人类细胞中的基因组稳定性依赖于双链 DNA 断裂的有效修复，这主要是通过同源重组 (HR) 实现的。在各种细胞功能的调节剂中，蛋白磷酸酶 4 (PP4) 在协调细胞对 DNA 损伤的反应方面起着关键作用。同时，Centrobin (CNTRB) 最初因其与中心体功能和微管动力学的关联而受到关注，但其在 DNA 修复过程中的潜在贡献也引起了人们的兴趣。在这项研究中，我们研究了 PP4 及其与 CNTRB 在人类细胞中 HR 介导的 DNA 修复中的相互作用。我们采用了一系列实验策略，研究了 PP4 和 CNTRB 之间的物理相互作用，并阐明了 CNTRB 中两个特定基序（PP4 结合 FRVP 和 ATR 激酶识别 SQ 序列）在 DNA 修复过程中的重要性。此外，我们还研究了敲除 PP4 或 CNTRB 的细胞以及 CNTRB 中 FRVP 和 SQ 突变的细胞，这些细胞表现出类似的异常染色体形态。这一现象可能是由于 Holliday 连接的分辨率受损所致，Holliday 连接是 HR 中的关键中间体。总之，我们的研究结果为 PP4 和 CNTRB 调控的 HR 修复的复杂机制及其相互关系提供了新的见解。
