Suppressor of gamma response 1 ( SOG1 ) encodes a putative transcription factor governing multiple responses to DNA damage

Abstract

The Arabidopsis sog1-1 (suppressor of gamma response) mutant was originally isolated as a second-site suppressor of the radiosensitive phenotype of seeds defective in the repair endonuclease XPF. Here, we report that SOG1 encodes a putative transcription factor. This gene is a member of the NAC domain [petunia NAM (no apical meristem) and Arabidopsis ATAF1,2 and CUC2] family (a family of proteins unique to land plants). Hundreds of genes are normally up-regulated in Arabidopsis within an hour of treatment with ionizing radiation; the induction of these genes requires the damage response protein kinase ATM, but not the related kinase ATR. Here, we find that SOG1 is also required for this transcriptional up-regulation. In contrast, the SOG1-dependent checkpoint response observed in xpf mutant seeds requires ATR, but does not require ATM. Thus, phenotype of the sog1-1 mutant mimics aspects of the phenotypes of both atr and atm mutants in Arabidopsis, suggesting that SOG1 participates in pathways governed by both of these sensor kinases. We propose that, in plants, signals related to genomic stress are processed through a single, central transcription factor, SOG1.Arabidopsis ͉ ATM ͉ ATR ͉ checkpoint response ͉ XPF

The plant‐specific CDKB 1‐ CYCB 1 complex mediates homologous recombination repair in Arabidopsis

“…At the same time, it was previously found that upregulation of CYCB1;1 after DNA damage requires SOG1 (Yoshiyama et al , 2009). Here, we have shown that SOG1 binds to the promoter of CYCB1;1 and hence appears to directly activate its expression presumably promoting CDKB1 activity and the execution of HR.…”

“…Previously, it was found that CYCB1;1 upregulation depends on ATM and SOG1 (Culligan et al , 2006; Yoshiyama et al , 2009). To test therefore whether CYCB1;1 and CDKB1s are directly regulated by SOG1, we performed ChIP experiments with plants expressing a tagged SOG1 version grown on cisplatin.…”

“…SOG1 is a central regulator of DNA damage response in plants that mediates checkpoint signaling (Yoshiyama et al , 2009, 2013). Previously, it was found that CYCB1;1 upregulation depends on ATM and SOG1 (Culligan et al , 2006; Yoshiyama et al , 2009).…”

“…In Arabidopsis , the transcriptional repression of CDKB2s depends on the putative transcription factor SOG1 that plays a key role in DNA damage response in Arabidopsis (Yoshiyama et al , 2009). At the same time, it was previously found that upregulation of CYCB1;1 after DNA damage requires SOG1 (Yoshiyama et al , 2009).…”

Subgroup-specific intrinsic disorder profiles of arabidopsis NAC transcription factors: Identification of functional hotspots

“…Members of this subgroup contain an Nterminal extension of the NAC domain (Fig. 1B) and have diverse functions in e.g., responses to DNA damage (SOG1) 24 and secondary cell wall development Bank accession 1UT7) followed by a disordered C-terminus (different conformers in gray) encompassing transcription regulatory activity and a large interaction potential. 10 (B) Predicted disorder plotted as a function of alignment position for representative NAC proteins.…”