Related Experiment Video
Updated: Aug 17, 2026

Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae
Published on: July 19, 2021
Protein translocation into mitochondria
1Institut für Biochemie und Molekularbiologie, Universität Freiburg, Germany.
Abstract:
The biogenesis of mitochondria requires the translocation of most mitochondrial proteins across two biological membranes. Mitochondrial preproteins are synthesized in the cytosol carrying targeting information, that is recognized by specific receptor proteins. The precursor polypeptides are transported across both mitochondrial membranes via three large integral membrane protein complexes forming specialized preprotein translocases. A soluble protein complex in the matrix provides the ATP-dependent translocation force, responsible for the movement and unfolding of the bulk polypeptide chain. After the removal of the targeting sequence, imported proteins fold into their native conformation with the help of chaperone proteins in the mitochondrial matrix.
Related Concept Videos
Overview of Protein Sorting and Transport
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded...
Mitochondrial Protein Sorting
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
Mitochondrial Precursor Proteins
Most of the mitochondrial precursors...
Translocation of Proteins into the Mitochondria
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Energy to Drive Translocation
Generally, polypeptides are unfolded by two distinct...
Protein Transport into the Inner Mitochondrial Membrane
Transport of mitochondrial precursors across the TIM23 channel is driven by...

