A regulatory phosphorylation site on Mec1 controls chromatin occupancy of RNA polymerases during replication stress.
EMBO J
; 40(21): e108439, 2021 11 02.
Article
em En
| MEDLINE
| ID: mdl-34569643
ABSTRACT
Upon replication stress, budding yeast checkpoint kinase Mec1ATR triggers the downregulation of transcription, thereby reducing the level of RNA polymerase (RNAP) on chromatin to facilitate replication fork progression. Here, we identify a hydroxyurea-induced phosphorylation site on Mec1, Mec1-S1991, that contributes to the eviction of RNAPII and RNAPIII during replication stress. The expression of the non-phosphorylatable mec1-S1991A mutant reduces replication fork progression genome-wide and compromises survival on hydroxyurea. This defect can be suppressed by destabilizing chromatin-bound RNAPII through a TAP fusion to its Rpb3 subunit, suggesting that lethality in mec1-S1991A mutants arises from replication-transcription conflicts. Coincident with a failure to repress gene expression on hydroxyurea in mec1-S1991A cells, highly transcribed genes such as GAL1 remain bound at nuclear pores. Consistently, we find that nuclear pore proteins and factors controlling RNAPII and RNAPIII are phosphorylated in a Mec1-dependent manner on hydroxyurea. Moreover, we show that Mec1 kinase also contributes to reduced RNAPII occupancy on chromatin during an unperturbed S phase by promoting degradation of the Rpb1 subunit.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
RNA Polimerase II
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RNA Polimerase III
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Processamento de Proteína Pós-Traducional
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Proteínas Serina-Treonina Quinases
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Proteínas de Saccharomyces cerevisiae
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Peptídeos e Proteínas de Sinalização Intracelular
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Replicação do DNA
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article