1
|
Kojima K, Ohkubo H, Kawasumi R, Hirota K. Pold4 subunit of replicative polymerase δ promotes fork slowing at broken templates. DNA Repair (Amst) 2024; 139:103688. [PMID: 38678695 DOI: 10.1016/j.dnarep.2024.103688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/25/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
Single-strand breaks (SSBs) are the most frequent type of lesion, and replication across such lesions leads to double-strand breaks (DSBs). DSBs that arise during replication are repaired by homologous recombination (HR) and are suppressed by fork reversal. Poly[ADP-ribose] polymerase I (PARP1) and the proofreading exonuclease activity of replicative polymerase ε (Polε) are required for fork reversal when leading strand replication encounters SSBs. However, the mechanism underlying fork reversal at the SSB during lagging-strand replication remains elusive. We here demonstrate that the Pold4 subunit of replicative polymerase δ (Polδ) plays a role in promoting fork reversal during lagging strand replication on a broken template. POLD4-/- cells exhibited heightened sensitivity to camptothecin (CPT) but not to other DNA-damaging agents compared to wild-type cells. This selective CPT sensitivity in POLD4-/- cells suggests that Pold4 suppresses DSBs during replication, as CPT induces significant SSBs during replication, which subsequently lead to DSBs. To explore the functional interactions among Pold4, Polε exonuclease, and PARP1 in DSB suppression, we generated PARP1-/-, POLD4-/-, Polε exonuclease-deficient POLE1exo-/-, PARP1-/-/POLD4-/-, and POLD4-/-/POLE1exo-/- cells. These epistasis analyses showed that Pold4 is involved in the PARP1-Polε exonuclease-mediated fork reversal following CPT treatment. These results suggest that Pold4 aids in fork reversal when lagging strand replication stalls on a broken template. In conclusion, the Pold4 subunit of Polδ has roles in the PARP1-Polε exonuclease-mediated fork reversal, contributing to the suppression of DSBs.
Collapse
Affiliation(s)
- Kota Kojima
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Hiromori Ohkubo
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Ryotaro Kawasumi
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan.
| |
Collapse
|
2
|
Xu S, Wei J, Sun S, Zhang J, Chan TF, Li Y. SSBlazer: a genome-wide nucleotide-resolution model for predicting single-strand break sites. Genome Biol 2024; 25:46. [PMID: 38347618 PMCID: PMC10863285 DOI: 10.1186/s13059-024-03179-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 01/24/2024] [Indexed: 02/15/2024] Open
Abstract
Single-strand breaks are the major DNA damage in the genome and serve a crucial role in various biological processes. To reveal the significance of single-strand breaks, multiple sequencing-based single-strand break detection methods have been developed, which are costly and unfeasible for large-scale analysis. Hence, we propose SSBlazer, an explainable and scalable deep learning framework for single-strand break site prediction at the nucleotide level. SSBlazer is a lightweight model with robust generalization capabilities across various species and is capable of numerous unexplored SSB-related applications.
Collapse
Affiliation(s)
- Sheng Xu
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
- Research Institute of Intelligent Complex Systems, Fudan University, 220 Handan Rd, Shanghai, 200437, China
- Shanghai AI Lab, 422 Jingan Rd, 200041, Shanghai, China
| | - Junkang Wei
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China.
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, USA.
| | - Siqi Sun
- Research Institute of Intelligent Complex Systems, Fudan University, 220 Handan Rd, Shanghai, 200437, China
- Shanghai AI Lab, 422 Jingan Rd, 200041, Shanghai, China
| | - Jizhou Zhang
- School of Life Sciences, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
| | - Ting-Fung Chan
- School of Life Sciences, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China
| | - Yu Li
- Department of Computer Science and Engineering, The Chinese University of Hong Kong, 100871, Hong Kong SAR, China.
- The CUHK Shenzhen Research Institute, Hi-Tech Park, Nanshan, 518057, Shenzhen, China.
| |
Collapse
|
3
|
Gao Y, Wu H, Wang Y, Liu X, Chen L, Li Q, Cui C, Liu X, Zhang J, Zhang Y. Single Cas9 nickase induced generation of NRAMP1 knockin cattle with reduced off-target effects. Genome Biol 2017; 18:13. [PMID: 28143571 PMCID: PMC5286826 DOI: 10.1186/s13059-016-1144-4] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/21/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The CRISPR-Cas9 system is a widely utilized platform for transgenic animal production in various species, although its off-target effects should be addressed. Several applications of this tool have been proposed in model animals but remain insufficient for transgenic livestock production. RESULTS Here, we report the first application of single Cas9 nickase (Cas9n) to induce gene insertion at a selected locus in cattle. We identify the main binding sites of a catalytically inactive Cas9 (dCas9) protein in bovine fetal fibroblast cells (BFFs) with chromatin immunoprecipitation sequencing (ChIP-seq). Subsequently, we demonstrate that a single Cas9n-induced single-strand break can stimulate the insertion of the natural resistance-associated macrophage protein-1 (NRAMP1) gene with reduced, but still considerable, off-target effects. Through somatic cell nuclear transfer, we finally obtain transgenic cattle with increased resistance to tuberculosis. CONCLUSIONS Our results contribute to the development of CRISPR-Cas9 system for agriculture applications.
Collapse
Affiliation(s)
- Yuanpeng Gao
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Haibo Wu
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yongsheng Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xin Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Linlin Chen
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Qian Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Chenchen Cui
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xu Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jingcheng Zhang
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yong Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China.
- Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| |
Collapse
|