Rap1 relocalization contributes to the chromatin-mediated gene expression profile and pace of cell senescence
| Autor: | Steven P. Barrett, Li-San Wang, Stephen R. Master, M. Dan Ricketts, Shufei Song, F. Brad Johnson, Alejandro Chavez, Khaled Omar Abdallah, Greg Donahue, Paul Ryvkin, Jesse M. Platt, Hannah J. Waters, Jennifer J. Wanat |
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| Rok vydání: | 2013 |
| Předmět: |
Senescence
endocrine system Saccharomyces cerevisiae Proteins Telomere-Binding Proteins Saccharomyces cerevisiae Repressor Shelterin Complex Histones Gene Expression Regulation Fungal Gene expression Genetics Microbial Viability biology Telomere biology.organism_classification Molecular biology Chromatin Protein Transport enzymes and coenzymes (carbohydrates) Histone biology.protein Rap1 Transcriptome Research Paper Transcription Factors Developmental Biology |
| Zdroj: | Genes & Development. 27:1406-1420 |
| ISSN: | 1549-5477 0890-9369 |
| DOI: | 10.1101/gad.218776.113 |
| Popis: | Cellular senescence is accompanied by dramatic changes in chromatin structure and gene expression. Using Saccharomyces cerevisiae mutants lacking telomerase (tlc1Δ) to model senescence, we found that with critical telomere shortening, the telomere-binding protein Rap1 (repressor activator protein 1) relocalizes to the upstream promoter regions of hundreds of new target genes. The set of new Rap1 targets at senescence (NRTS) is preferentially activated at senescence, and experimental manipulations of Rap1 levels indicate that it contributes directly to NRTS activation. A notable subset of NRTS includes the core histone-encoding genes; we found that Rap1 contributes to their repression and that histone protein levels decline at senescence. Rap1 and histones also display a target site-specific antagonism that leads to diminished nucleosome occupancy at the promoters of up-regulated NRTS. This antagonism apparently impacts the rate of senescence because underexpression of Rap1 or overexpression of the core histones delays senescence. Rap1 relocalization is not a simple consequence of lost telomere-binding sites, but rather depends on the Mec1 checkpoint kinase. Rap1 relocalization is thus a novel mechanism connecting DNA damage responses (DDRs) at telomeres to global changes in chromatin and gene expression while driving the pace of senescence. |
| Databáze: | OpenAIRE |
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