title: Ca2+-induced permeability transition can be observed even in yeast mitochondria under optimized experimental conditions.
abstract: Yeast mitochondria have generally been believed not to undergo the permeability transition (PT) by the accumulation of Ca(2+) within the mitochondrial matrix, unlike mammalian mitochondria. However, the reason why the yeast PT is not induced by Ca(2+) has remained obscure. In this study, we examined in detail the effects of Ca(2+) on yeast mitochondria under various conditions. As a result, we discovered that the PT could be induced even in yeast mitochondria by externally added Ca(2+) under optimized experimental conditions. The 2 essential parameters for proper observation of the PT-inducing effects of Ca(2+) were the concentrations of the respiratory substrate and that of inorganic phosphate (Pi) in the incubation medium. The yeast mitochondrial PT induced by Ca(2+) was found to be insensitive to cyclosporin A and suppressed in the presence of a high concentration of Pi. Furthermore, when the PT was induced in yeast mitochondria by Ca(2+), the release of cytochrome c from mitochondria was also observed.
authors.affiliation: School of Dentistry, University of Tokushima, Tokushima 770-8504, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Yamada
authors.forename: Takenori
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Yuya
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Shunichi
authors.initials: S
authors.lastname: Gouda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kawashima
authors.forename: Naoshi
authors.initials: N
authors.lastname: Yamazaki
authors.forename: Kikuji
authors.initials: K
authors.lastname: Yamashita
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kataoka
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Nagata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Terada
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Pfeiffer
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Shinohara
mesh_terms: D002118:Calcium / Q000378:metabolism*; D045304:Cytochromes c / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D015003:Yeasts / Q000378:metabolism*
chemical_list: D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D045304:Cytochromes c; D002118:Calcium