Open AccessImport of proteins into mitochondria: a multi‐step process
Author(s) -
PFANNER Nikolaus,
HARTL FranzUlrich,
NEUPERT Walter
Publication year - 1988
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1988.tb14185.x
Subject(s) - protein targeting , mitochondrion , microbiology and biotechnology , cytosol , chromosomal translocation , translocase of the inner membrane , intermembrane space , transport protein , chemistry , mitochondrial membrane transport protein , biochemistry , inner mitochondrial membrane , biology , membrane , membrane protein , bacterial outer membrane , gene , enzyme , escherichia coli
Translocation of precursor proteins from the cytosol into mitochondria is a multi‐step process. The generation of translocation intermediates, i.e. the reversible accumulation of precursors at distinct stages of their import pathway into mitochondria (‘translocation arrest’), has allowed the experimental characterization of distinct functional steps of protein import. These steps include: ATP‐dependent unfolding of precursors; specific recognition of precursors by distinct receptors on the mitochondrial surface; interaction of precursors with a general insertion protein (‘GIP’) in the outer mitochondrial membrane; membrane‐potential‐dependent translocation into the inner membrane at contact sites between both membranes; proteolytic processing of precursors; and intramitochondrial sorting of precursors via the matrix space (‘conservative sorting’). The functional characteristics unveiled by studying mitochondrial protein import appear to be of general interest for investigations on intracellular protein sorting.