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Why mitochondria need a genome revisited
Author(s) -
Björkholm Patrik,
Ernst Andreas M.,
Hagström Erik,
Andersson Siv G. E.
Publication year - 2017
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.12510
Subject(s) - mitochondrion , cytosol , endoplasmic reticulum , nuclear gene , biology , gene , mitochondrial dna , microbiology and biotechnology , genome , subcellular localization , genetics , biochemistry , enzyme
In this paper, we experimentally address the debate about why functional transfer of mitochondrial genes to the nucleus has been halted in some organismal groups and why cytosolic expression of mitochondrial proteins has proven remarkably difficult. By expressing all 13 human mitochondrial‐encoded genes with strong mitochondrial‐targeting sequences in the cytosol of human cells, we show that all proteins, except ATP 8, are transported to the endoplasmic reticulum (ER). These results confirm and extend previous findings based on three mitochondrial genes lacking mitochondrial‐targeting sequences that also were relocated to the ER during cytosolic expression. We conclude that subcellular protein targeting constitutes a major barrier to functional transfer of mitochondrial genes to the nuclear genome.