An interplay between the TOM complex and porin isoforms in the yeast Saccharomyces cerevisiae mitochondria.
The outer mitochondrial membrane of Saccharomyces cerevisiae contains two isoforms of mitochondrial porin, known also as the voltage-dependent anion channel. The isoform termed here porin1 displays channel-forming activity enabling metabolite transport whereas the second one, termed here porin2, does not form a channel and its function is still not clear. We have shown recently that in the absence of porin1, the channel within the protein import machinery (the TOM complex) is essential for metabolite transport across the outer membrane [Kmita and Budzińska, Biochim. Biophys. Acta 1509 (2000) 6044-6050]. Here, we report that the TOM complex channel may also serve as a supplementary pathway for metabolites in the presence of porin1 when the permeability of the latter is limited and the role of the TOM complex seems to increase when porin2 is depleted.
Antos
N
N
Institute of Molecular Biology and Biotechnology, Department of Bioenergetics, Adam Mickiewicz University, Fredry 10, 61-701 Poznan, Poland.
Budzińska
M
M
Kmita
H
H
D001692:Biological Transport / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism*; D017353:Gene Deletion; D007425:Intracellular Membranes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D018272:Porins / Q000172:deficiency / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism; D015854:Up-Regulation
D002352:Carrier Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D018272:Porins; D020033:Protein Isoforms; D009243:NAD; D013762:Tetrahydrofolate Dehydrogenase