title: γ-Glutamyl kinase is involved in selective autophagy of ribosomes in Saccharomyces cerevisiae.
abstract: γ-Glutamyl kinase (GK; the PRO1 gene product) is a key enzyme in the Saccharomyces cerevisiae proline biosynthesis pathway. Δpro1 cells are more sensitive to various stresses than wild-type cells, suggesting that GK has an alternative function independent of proline biosynthesis. We show that PRO1 genetically interacts with UBP3, which encodes ubiquitin-specific protease, and is required for selective autophagy of ribosomes (ribophagy). Interestingly, yeast cells with PRO1 deletion or expressing inactive GK display a defect for ribophagy but not for nonselective autophagy, indicating that GK activity is indispensable for ribophagy. Gene disruption analysis suggests that ribophagy is important for cell survival during nitrogen starvation.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tatehashi
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Watanabe
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takagi
mesh_terms: D001343:Autophagy / Q000235:genetics*; D053898:Biosynthetic Pathways / Q000235:genetics; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D017851:Phosphotransferases (Carboxyl Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D011392:Proline / Q000096:biosynthesis; D012270:Ribosomes / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013217:Starvation; D025801:Ubiquitin / Q000378:metabolism
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; D011392:Proline; D017851:Phosphotransferases (Carboxyl Group Acceptor); C020650:glutamate 5-kinase; D010450:Endopeptidases; C101111:UBP3 protein, S cerevisiae
keywords: autophagy; deubiquitination; ribophagy; ribosome; yeast; γ-glutamyl kinase