Gcn5-mediated Rph1 acetylation regulates its autophagic degradation under DNA damage stress.
Histone modifiers regulate proper cellular activities in response to various environmental stress by modulating gene expression. In budding yeast, Rph1 transcriptionally represses many DNA damage or autophagy-related gene expression. However, little is known how Rph1 is regulated during these stress conditions. Here, we report that Rph1 is degraded upon DNA damage stress conditions. Notably, this degradation occurs via the autophagy pathway rather than through 26S proteasome proteolysis. Deletion of ATG genes or inhibition of vacuole protease activity compromises Rph1 turnover. We also determine that Rph1 and nuclear export protein Crm1 interact, which is required for Rph1 translocation from the nucleus to the cytoplasm. More importantly, Gcn5 directly acetylates Rph1 in vitro and in vivo, and Gcn5-containing complex, SAGA, is required for autophagic degradation of Rph1. Gcn5-mediated Rph1 acetylation is essential for the association of Rph1 with the nuclear pore protein Nup1. Finally, we show that sustaining high levels of Rph1 during DNA damage stress results in cell growth defects. Thus, we propose that Gcn5-mediated acetylation finely regulates Rph1 protein level and that autophagic degradation of Rph1 is important for cell homeostasis. Our findings may provide a general connection between DNA damage, protein acetylation and autophagy.
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China.
Feng
F
Li
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China.
Liang-De
LD
Zheng
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China.
Xin
X
Chen
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China.
Xiaolu
X
Zhao
Department of Biochemistry and Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
Scott D
SD
Briggs
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China.
Hai-Ning
HN
Du
D000107:Acetylation / Q000187:drug effects; D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D004249:DNA Damage; D051548:Histone Acetyltransferases / Q000378:metabolism*; D056466:Histone Demethylases / Q000378:metabolism*; D006706:Homeostasis / Q000187:drug effects; D028884:Karyopherins / Q000378:metabolism; D008741:Methyl Methanesulfonate / Q000633:toxicity; D008954:Models, Biological; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D059748:Proteolysis / Q000187:drug effects; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013312:Stress, Physiological / Q000187:drug effects; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism; D000097606:Exportin 1 Protein; D000099224:p300-CBP-Associated Factor
D051548:Histone Acetyltransferases; D056466:Histone Demethylases; D028884:Karyopherins; D008741:Methyl Methanesulfonate; D046988:Proteasome Endopeptidase Complex; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D000097606:Exportin 1 Protein; C400296:RPH1 protein, S cerevisiae; C501392:GCN5 protein, S cerevisiae; D000099224:p300-CBP-Associated Factor