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Investigation of the Yeast Mitochondriai Unselective Channel in intact and permeabilized spheroplasts
Author(s) -
Ma Stéphen,
Guérin Martine
Publication year - 1998
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549800201602
Subject(s) - spheroplast , yeast , mitochondrion , biochemistry , biology , membrane potential , biophysics , cellular respiration , inner membrane , atp synthase , microbiology and biotechnology , enzyme , escherichia coli , gene
The existence of an activity corresponding to the nucleotide‐induced Yeast Mitochondria Unselective Channel (YMUC2) of isolated mitochondria was investigated in permeabilized and intact spheroplasts of the baker's yeast Yeast Foam. In nystatin‐permeabilized spheroplasts, ATP and GDP‐β‐S induced a decavanadate‐sensitive stimulation of the respiration only under conditions equivalent to those previously reported for isolated mitochondria (low phosphate concentration, presence of a salt). On intact spheroplasts, parallel measurements of respiration rate, [ATP]/[ADP] ratio and mitochondrial transmembrane potential allowed to show that the addition of the glucose analog 2‐deoxyglucose decreased the permeability of the inner mitochondrial membrane owing to cellular ATP depletion. This strongly supports the hypothesis that Yeast Mitochondria Unspecific Channel is active in situ and inhibited by cellular [ATP] depletion.