A stress-blinded Atf1 can fully assemble heterochromatin in a RNAi-independent minimal mat locus but impairs directionality of mat2/3 switching
Summary: The MAP kinase Sty1 phosphorylates and activates the transcription factor Atf1 in response to several stress conditions, which then shifts from a transcriptional repressor to an activator. Atf1 also participates in heterochromatin assembly at the mat locus, in combination with the RNA inter...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-08-01
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| Series: | iScience |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2589004222010926 |
| _version_ | 1798042825765421056 |
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| author | Rodrigo Fraile Laura Sánchez-Mir Guillem Murciano-Julià José Ayté Elena Hidalgo |
| author_facet | Rodrigo Fraile Laura Sánchez-Mir Guillem Murciano-Julià José Ayté Elena Hidalgo |
| author_sort | Rodrigo Fraile |
| collection | DOAJ |
| description | Summary: The MAP kinase Sty1 phosphorylates and activates the transcription factor Atf1 in response to several stress conditions, which then shifts from a transcriptional repressor to an activator. Atf1 also participates in heterochromatin assembly at the mat locus, in combination with the RNA interference (RNAi) machinery. Here, we study the role of signal-dependent phosphorylation of Atf1 in heterochromatin establishment at mat, using different Atf1 phospho mutants. Although a hypo-phosphorylation Atf1 mutant, Atf1.10M, mediates heterochromatin assembly, the phosphomimic Atf1.10D is unable to maintain silencing. In a minimal mat locus, lacking the RNAi-recruiting cis elements and displaying intermediate silencing, Atf1.10M restores full heterochromatin and silencing. However, evolution experiments with this stress-blinded Atf1.10M show that it is unable to facilitate switching between the donor site mat3 and mat1. We propose that the unphosphorylated, inactive Atf1 contributes to proper heterochromatin assembly by recruiting repressive complexes, but its stress-dependent phosphorylation is required for recombination/switching to occur. |
| first_indexed | 2024-04-11T22:41:01Z |
| format | Article |
| id | doaj.art-e2ad93eac4bb47b3bbaf73dcb9051cd9 |
| institution | Directory Open Access Journal |
| issn | 2589-0042 |
| language | English |
| last_indexed | 2024-04-11T22:41:01Z |
| publishDate | 2022-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | iScience |
| spelling | doaj.art-e2ad93eac4bb47b3bbaf73dcb9051cd92022-12-22T03:59:00ZengElsevieriScience2589-00422022-08-01258104820A stress-blinded Atf1 can fully assemble heterochromatin in a RNAi-independent minimal mat locus but impairs directionality of mat2/3 switchingRodrigo Fraile0Laura Sánchez-Mir1Guillem Murciano-Julià2José Ayté3Elena Hidalgo4Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, SpainOxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, SpainOxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, SpainOxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, SpainOxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain; Corresponding authorSummary: The MAP kinase Sty1 phosphorylates and activates the transcription factor Atf1 in response to several stress conditions, which then shifts from a transcriptional repressor to an activator. Atf1 also participates in heterochromatin assembly at the mat locus, in combination with the RNA interference (RNAi) machinery. Here, we study the role of signal-dependent phosphorylation of Atf1 in heterochromatin establishment at mat, using different Atf1 phospho mutants. Although a hypo-phosphorylation Atf1 mutant, Atf1.10M, mediates heterochromatin assembly, the phosphomimic Atf1.10D is unable to maintain silencing. In a minimal mat locus, lacking the RNAi-recruiting cis elements and displaying intermediate silencing, Atf1.10M restores full heterochromatin and silencing. However, evolution experiments with this stress-blinded Atf1.10M show that it is unable to facilitate switching between the donor site mat3 and mat1. We propose that the unphosphorylated, inactive Atf1 contributes to proper heterochromatin assembly by recruiting repressive complexes, but its stress-dependent phosphorylation is required for recombination/switching to occur.http://www.sciencedirect.com/science/article/pii/S2589004222010926Molecular biologyMolecular mechanism of gene regulationEpigeneticsFunctional aspects of cell biology |
| spellingShingle | Rodrigo Fraile Laura Sánchez-Mir Guillem Murciano-Julià José Ayté Elena Hidalgo A stress-blinded Atf1 can fully assemble heterochromatin in a RNAi-independent minimal mat locus but impairs directionality of mat2/3 switching iScience Molecular biology Molecular mechanism of gene regulation Epigenetics Functional aspects of cell biology |
| title | A stress-blinded Atf1 can fully assemble heterochromatin in a RNAi-independent minimal mat locus but impairs directionality of mat2/3 switching |
| title_full | A stress-blinded Atf1 can fully assemble heterochromatin in a RNAi-independent minimal mat locus but impairs directionality of mat2/3 switching |
| title_fullStr | A stress-blinded Atf1 can fully assemble heterochromatin in a RNAi-independent minimal mat locus but impairs directionality of mat2/3 switching |
| title_full_unstemmed | A stress-blinded Atf1 can fully assemble heterochromatin in a RNAi-independent minimal mat locus but impairs directionality of mat2/3 switching |
| title_short | A stress-blinded Atf1 can fully assemble heterochromatin in a RNAi-independent minimal mat locus but impairs directionality of mat2/3 switching |
| title_sort | stress blinded atf1 can fully assemble heterochromatin in a rnai independent minimal mat locus but impairs directionality of mat2 3 switching |
| topic | Molecular biology Molecular mechanism of gene regulation Epigenetics Functional aspects of cell biology |
| url | http://www.sciencedirect.com/science/article/pii/S2589004222010926 |
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