Phosphorylation of Rph1, a damage-responsive repressor of PHR1 in Saccharomyces cerevisiae, is dependent upon Rad53 kinase

Abstract

Rph1, a Cys2-His2 zinc finger protein, binds to an upstream repressing sequence of the photolyase gene PHR1, and represses its transcription in response to DNA damage in Saccharomyces cerevisiae. In this report, we have demonstrated that the phosphorylation of Rph1 protein was increased in response to DNA damage. The DNA damage-induced phosphorylation of Rph1 was missing in most damage checkpoint mutants including rad9, rad17, mec1 and rad53. These results indicate that Rph1 phosphorylation is under the control of the Mec1-Rad53 damage checkpoint pathway. Rph1 phosphorylation required the kinase activity of Rad53 since it was significantly decreased in rad53 checkpoint mutant. Furthermore, loss of other kinases including Dun1, Tel1 and Chk1, which function downstream of Mec1, did not affect the Rph1 phosphorylation. This contrasts with the derepression of Crt1-regulated genes, which requires both Rad53 and Dun1 protein kinases. These results imply that posttranslational modification of Rph1 repressor is regulated by a potentially novel damage checkpoint pathway that is distinct from the RAD53-DUN1-CRT1 cascade implicated in the DNA damage-dependent transcription of ribonucleotide reductase genes.

AG4sequence withinPHR1promoter acts as a gate for cross‐talks between damage‐signaling pathway and multi‐stress response

“…These data indicate that PHR1 induction is controlled by the Dunl-independent pathway for transducing the damage signal to Rphl-Gisl repressors (Sancar, 2000). In the previous report, we have demonstrated that Rphl was hyperphosphorylated by the Rad53-dependent checkpoint pathway but not by the Dunl protein kinase, supporting that the regulation of PHR1 expression by Rphl is not Dunl-de pendent (Kim et al, 2002).…”

Checkpoint Kinases Regulate a Global Network of Transcription Factors in Response to DNA Damage

“…(Rfx1 was not examined because its phosphoregulation by Rad53 and Dun1 has been described by Huang et al (1998). Also note that Rph1, an additional TF included in Figure S1, has been shown to undergo Rad53-dependent, DNA damage-induced phosphorylation (Kim et al, 2002). ) The rad53Δ mutant was the focus of this analysis because virtually the entire checkpoint-kinase-mediated transcriptional response to MMS was Rad53 dependent (Figures 1C and 3C).…”

A pathway of targeted autophagy is induced by DNA damage in budding yeast

“…Rph1 negatively regulates the transcription of the photolyase gene PHR1 that mediates resistance to UV-induced DNA damage (37). Rph1 is also phosphorylated in a Rad53-dependent manner after DNA damage, which causes its dissociation from chromatin, thereby relieving repression of target genes (38). Given that Rph1 acts as an autophagy repressor (36) and is also linked to the DDR, we investigated whether Rph1 plays any role in ATG gene transcription after DNA damage.…”