Multi-step processing of replication stress-derived nascent strand DNA gaps by MRE11 and EXO1 nucleases
Abstract Accumulation of single stranded DNA (ssDNA) gaps in the nascent strand during DNA replication has been associated with cytotoxicity and hypersensitivity to genotoxic stress, particularly upon inactivation of the BRCA tumor suppressor pathway. However, how ssDNA gaps contribute to genotoxici...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2023-10-01
|
| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-023-42011-0 |
| _version_ | 1797558350018248704 |
|---|---|
| author | Anastasia Hale Ashna Dhoonmoon Joshua Straka Claudia M. Nicolae George-Lucian Moldovan |
| author_facet | Anastasia Hale Ashna Dhoonmoon Joshua Straka Claudia M. Nicolae George-Lucian Moldovan |
| author_sort | Anastasia Hale |
| collection | DOAJ |
| description | Abstract Accumulation of single stranded DNA (ssDNA) gaps in the nascent strand during DNA replication has been associated with cytotoxicity and hypersensitivity to genotoxic stress, particularly upon inactivation of the BRCA tumor suppressor pathway. However, how ssDNA gaps contribute to genotoxicity is not well understood. Here, we describe a multi-step nucleolytic processing of replication stress-induced ssDNA gaps which converts them into cytotoxic double stranded DNA breaks (DSBs). We show that ssDNA gaps are extended bidirectionally by MRE11 in the 3’−5’ direction and by EXO1 in the 5’−3’ direction, in a process which is suppressed by the BRCA pathway. Subsequently, the parental strand at the ssDNA gap is cleaved by the MRE11 endonuclease generating a double strand break. We also show that exposure to bisphenol A (BPA) and diethylhexyl phthalate (DEHP), which are widespread environmental contaminants due to their use in plastics manufacturing, causes nascent strand ssDNA gaps during replication. These gaps are processed through the same mechanism described above to generate DSBs. Our work sheds light on both the relevance of ssDNA gaps as major determinants of genomic instability, as well as the mechanism through which they are processed to generate genomic instability and cytotoxicity. |
| first_indexed | 2024-03-10T17:28:59Z |
| format | Article |
| id | doaj.art-fd6a77a2b70d4ad48b428ac71575a32e |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-03-10T17:28:59Z |
| publishDate | 2023-10-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-fd6a77a2b70d4ad48b428ac71575a32e2023-11-20T10:05:49ZengNature PortfolioNature Communications2041-17232023-10-0114111610.1038/s41467-023-42011-0Multi-step processing of replication stress-derived nascent strand DNA gaps by MRE11 and EXO1 nucleasesAnastasia Hale0Ashna Dhoonmoon1Joshua Straka2Claudia M. Nicolae3George-Lucian Moldovan4Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of MedicineDepartment of Biochemistry and Molecular Biology, The Pennsylvania State University College of MedicineDepartment of Biochemistry and Molecular Biology, The Pennsylvania State University College of MedicineDepartment of Biochemistry and Molecular Biology, The Pennsylvania State University College of MedicineDepartment of Biochemistry and Molecular Biology, The Pennsylvania State University College of MedicineAbstract Accumulation of single stranded DNA (ssDNA) gaps in the nascent strand during DNA replication has been associated with cytotoxicity and hypersensitivity to genotoxic stress, particularly upon inactivation of the BRCA tumor suppressor pathway. However, how ssDNA gaps contribute to genotoxicity is not well understood. Here, we describe a multi-step nucleolytic processing of replication stress-induced ssDNA gaps which converts them into cytotoxic double stranded DNA breaks (DSBs). We show that ssDNA gaps are extended bidirectionally by MRE11 in the 3’−5’ direction and by EXO1 in the 5’−3’ direction, in a process which is suppressed by the BRCA pathway. Subsequently, the parental strand at the ssDNA gap is cleaved by the MRE11 endonuclease generating a double strand break. We also show that exposure to bisphenol A (BPA) and diethylhexyl phthalate (DEHP), which are widespread environmental contaminants due to their use in plastics manufacturing, causes nascent strand ssDNA gaps during replication. These gaps are processed through the same mechanism described above to generate DSBs. Our work sheds light on both the relevance of ssDNA gaps as major determinants of genomic instability, as well as the mechanism through which they are processed to generate genomic instability and cytotoxicity.https://doi.org/10.1038/s41467-023-42011-0 |
| spellingShingle | Anastasia Hale Ashna Dhoonmoon Joshua Straka Claudia M. Nicolae George-Lucian Moldovan Multi-step processing of replication stress-derived nascent strand DNA gaps by MRE11 and EXO1 nucleases Nature Communications |
| title | Multi-step processing of replication stress-derived nascent strand DNA gaps by MRE11 and EXO1 nucleases |
| title_full | Multi-step processing of replication stress-derived nascent strand DNA gaps by MRE11 and EXO1 nucleases |
| title_fullStr | Multi-step processing of replication stress-derived nascent strand DNA gaps by MRE11 and EXO1 nucleases |
| title_full_unstemmed | Multi-step processing of replication stress-derived nascent strand DNA gaps by MRE11 and EXO1 nucleases |
| title_short | Multi-step processing of replication stress-derived nascent strand DNA gaps by MRE11 and EXO1 nucleases |
| title_sort | multi step processing of replication stress derived nascent strand dna gaps by mre11 and exo1 nucleases |
| url | https://doi.org/10.1038/s41467-023-42011-0 |
| work_keys_str_mv | AT anastasiahale multistepprocessingofreplicationstressderivednascentstranddnagapsbymre11andexo1nucleases AT ashnadhoonmoon multistepprocessingofreplicationstressderivednascentstranddnagapsbymre11andexo1nucleases AT joshuastraka multistepprocessingofreplicationstressderivednascentstranddnagapsbymre11andexo1nucleases AT claudiamnicolae multistepprocessingofreplicationstressderivednascentstranddnagapsbymre11andexo1nucleases AT georgelucianmoldovan multistepprocessingofreplicationstressderivednascentstranddnagapsbymre11andexo1nucleases |