title: Turnover of ATP synthase subunits in F1-depleted HeLa and yeast cells.
abstract: Mitochondrial translation of the Saccharomyces cerevisiae Atp6p subunit of F(1)-F(0) ATP synthase is regulated by the F(1) ATPase. Here we show normal expression of Atp6p in HeLa cells depleted of the F(1) β subunit. Instead of being translationally down-regulated, HeLa cells lacking F(1) degrade Atp6p, thereby preventing proton leakage across the inner membrane. Mammalian mitochondria also differ in the way they minimize the harmful effect of unassembled F(1) α subunit. While yeast mutants lacking β subunit have stable aggregated F(1) α subunit in the mitochondrial matrix, the human α subunit is completely degraded in cells deficient in F(1) β subunit. These results are discussed in light of the different properties of the proteins and environments in which yeast and human mitochondria exist.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Rak
authors.forename: Gavin P
authors.initials: GP
authors.lastname: McStay
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujikawa
authors.forename: Masasuke
authors.initials: M
authors.lastname: Yoshida
authors.forename: Giovanni
authors.initials: G
authors.lastname: Manfredi
authors.forename: Alexander
authors.initials: A
authors.lastname: Tzagoloff
mesh_terms: D000818:Animals; D002417:Cattle; D006367:HeLa Cells; D006801:Humans; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism; D025261:Mitochondrial Proton-Translocating ATPases / Q000096:biosynthesis / Q000378:metabolism*; D014176:Protein Biosynthesis; D021122:Protein Subunits / Q000737:chemistry / Q000172:deficiency* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000201:enzymology*; D012995:Solubility
chemical_list: C501005:MT-ATP6 protein, human; D021122:Protein Subunits; D025261:Mitochondrial Proton-Translocating ATPases