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Separate fusion of outer and inner mitochondrial membranes
Author(s) -
Malka Florence,
Guillery Olwenn,
CifuentesDiaz Carmen,
Guillou Emmanuelle,
Belenguer Pascale,
Lombès Anne,
Rojo Manuel
Publication year - 2005
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1038/sj.embor.7400488
Subject(s) - inner membrane , lipid bilayer fusion , translocase of the inner membrane , membrane , fusion mechanism , translocase of the outer membrane , inner mitochondrial membrane , fusion , bacterial outer membrane , biophysics , microbiology and biotechnology , chemistry , valinomycin , mitochondrion , biology , biochemistry , atp–adp translocase , mitochondrial membrane transport protein , linguistics , philosophy , escherichia coli , gene
Mitochondria are enveloped by two closely apposed boundary membranes with different properties and functions. It is known that they undergo fusion and fission, but it has remained unclear whether outer and inner membranes fuse simultaneously, coordinately or separately. We set up assays for the study of inner and outer membrane fusion in living human cells. Inner membrane fusion was more sensitive than outer membrane fusion to inhibition of glycolysis. Fusion of the inner membrane, but not of the outer membrane, was abolished by dissipation of the inner membrane potential with K + (valinomycin) or H + ionophores (cccp). In addition, outer and inner membrane fusion proceeded separately in the absence of any drug. The separate fusion of outer and inner membranes and the different requirements of these fusion reactions point to the existence of fusion machineries that can function separately.