The WEE1 and ATM AND RAD3-RELATED (ATR) kinases are important regulators of the plant intra-S-phase checkpoint; consequently, WEE1KO and ATRKO roots are hypersensitive to replication-inhibitory drugs. Here, we report on a loss-of-function mutant allele of the FASCIATA1 (FAS1) subunit of the chromatin assembly factor 1 (CAF-1) complex that suppresses the phenotype of WEE1- or ATR-deficient Arabidopsis (Arabidopsis thaliana) plants. We demonstrate that lack of FAS1 activity results in the activation of an ATAXIA TELANGIECTASIA MUTATED (ATM)- and SUPPRESSOR OF GAMMA-RESPONSE 1 (SOG1)-mediated G2/M-arrest that renders the ATR and WEE1 checkpoint regulators redundant. This ATM activation accounts for the telomere erosion and loss of ribosomal DNA that are described for fas1 plants. Knocking out SOG1 in the fas1 wee1 background restores replication stress sensitivity, demonstrating that SOG1 is an important secondary checkpoint regulator in plants that fail to activate the intra-S-phase checkpoint.

• MeSH
• Arabidopsis genetika   fyziologie   MeSH
• ATM protein genetika   metabolismus   MeSH
• fyziologický stres MeSH
• genom rostlinný MeSH
• nestabilita genomu MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• protoonkogenní proteiny c-myb genetika   metabolismus   MeSH
• replikace DNA * MeSH
• signální transdukce * MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ATM protein, Arabidopsis MeSH Prohlížeč
• ATM protein MeSH
• ATR1 protein, Arabidopsis MeSH Prohlížeč
• FAS protein, Arabidopsis MeSH Prohlížeč
• protein-serin-threoninkinasy MeSH
• proteiny huseníčku MeSH
• protoonkogenní proteiny c-myb MeSH
• SOG1 protein, Arabidopsis MeSH Prohlížeč
• transkripční faktory MeSH
• WEE1 protein, Arabidopsis MeSH Prohlížeč