Targeting of proteins to mitochondria

[摘要]

A clear picture has emerged over the past years on how a ‘classic’ mitochondrial protein, like subunit IV of cytochrome c oxidase, might be targeted to mitochondria. The targeting and subsequent import process involves the commitment of the TOM (ranslocase in the uter itochondrial membrane) receptor complex on the mitochondrial surface, a TIM (ranslocase in the nner itochondrial membrane) translocation complex in the mitochondrial inner membrane, and assorted chaperones and processing enzymes within the organelle. Recent work suggests that while very many mitochondrial precursor proteins might follow this basic targeting pathway, a large number have further requirements if they are to be successfully imported. These include ribosome-associated factors and soluble factors in the cytosol, soluble factors in the mitochondrial intermembrane space, an additional TIM translocase in the inner membrane and a range of narrow specificity assembly factors in the inner membrane. This review is focused on the targeting of proteins up to the stage at which they enter the TOM complex in the outer membrane.

[学科分类] 生物化学/生物物理

[关键词] Mitochondrion;Ribosome;Protein targeting;Membrane;Protein translocation