Precursors of mitochondrial proteins are degraded in the cytosol at different rates

Abstract
The stability of rat liver mitochondrial protein precursors in the cytosol was investigated. The precursors were synthesized in a post-mitochondrial supernatant from rat liver, and mitochondria were then added at different times. The amount and pattern of proteins incorporated were determined. The precursors have different rates of transport into mitochondria. Some precursors are stable in the cytosol while most are degraded rapidly, with a half-life of about 30 min at 30°C.