hide
Free keywords:
-
Abstract:
The human mitochondrial genome encodes thirteen core subunits of the oxidative phosphorylation system,
and defects in mitochondrial gene expression lead to severe neuromuscular disorders. However, the mech-
anisms of mitochondrial gene expression remain poorly understood due to a lack of experimental ap-
proaches to analyze these processes. Here, we present an in vitro system to silence translation in purified
mitochondria. In vitro import of chemically synthesized precursor-morpholino hybrids allows us to target
translation of individual mitochondrial mRNAs. By applying this approach, we conclude that the bicistronic,
overlapping ATP8/ATP6 transcript is translated through a single ribosome/mRNA engagement. We show that
recruitment of COX1 assembly factors to translating ribosomes depends on nascent chain formation. By
defining mRNA-specific interactomes for COX1 and COX2, we reveal an unexpected function of the cytosolic
oncofetal IGF2BP1, an RNA-binding protein, in mitochondrial translation. Our data provide insight into mitochondrial translation and innovative strategies to investigate mitochondrial gene expression.
