Mitochondrial protein import stress and signaling

Abstract

Mitochondrial proteins need to be efficiently imported by sophisticated machineries because the vast majority of them are encoded in the nucleus. Various mitochondrial dysfunctions and pathologies are often associated with energy depletion and oxidative stress. This stress triggers transcriptional and cytosolic responses, effects that depend on the type and duration of the signal from defective mitochondria. Mitochondrial stress can cause the accumulation of mitochondrial precursor proteins in the cytosol. Defective mitochondrial function, including the faulty supply of mitochondria with proteins, can be associated with diseases and aging. This review presents the consequences of mitochondrial import failure and adaptive responses to mitochondrial import failure that are induced to maintain mitochondrial and cellular protein homeostasis.