Principles of cotranslational mitochondrial protein import.

ABSTRACT: Nearly all mitochondrial proteins are translated on cytosolic ribosomes. How these proteins are subsequently delivered to mitochondria remains poorly understood. Using selective ribosome profiling, we show that nearly 20% of mitochondrial proteins can be imported cotranslationally in human cells. Cotranslational import requires an N-terminal presequence on the nascent protein and contributes to localized translation at the mitochondrial surface. This pathway does not favor membrane proteins but instead prioritizes large, multi-domain, topologically complex proteins, whose import efficiency is enhanced when targeted cotranslationally. In contrast to the early onset of cotranslational protein targeting to the endoplasmic reticulum (ER), the presequence on mitochondrial proteins is inhibited

SUBMITTER: Zhu Z 

PROVIDER: S-EPMC12396113 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature