C. Ballarin et Mc. Sorgato, ANION CHANNELS OF THE INNER MEMBRANE OF MAMMALIAN AND YEAST MITOCHONDRIA, Journal of bioenergetics and biomembranes, 28(2), 1996, pp. 125-130
The inner membrane of yeast and mammalian mitochondria has been studie
d in situ with a patch clamp electrode. Anion channels were found in b
oth cases, although their behavior and regulation are different. In ma
mmalian mitochondria, the principal channel is of around 100 pS conduc
tance and opens mainly under depolarized membrane potentials, As no ph
ysiological compound able to alter its peculiar voltage dependence has
yet been found, it is proposed that this channel may serve as a safeg
uard mechanism for recharging the mitochondrial membrane potential. Tw
o other anion channels, each with a distinct conductance (one of appro
x. 45 pS, the second of at least a tenfold higher value) and kinetics
are harbored in the yeast inner membrane. Matrix ATP was found to inte
ract with both, but with a different mechanism. It is proposed that th
e 45 pS channel may be involved in the homeostatic mechanism of mitoch
ondrial volume.