The cleavable prepiece of an imported mitochondrial protein is sufficient to direct cytosolic dihydrofolate reductase into the mitochondrial matrix

Abstract
The cleavable prepiece of the precursor to yeast cytochrome c oxidase subunit IV (an imported mitochondrial protein) was attached to the amino‐terminus of mouse dihydrofolate reductase (a cytosolic protein) by gene fusion. The resulting fusion protein was imported into the matrix of isolated, energized yeast mitochondria and cleaved to a polypeptide whose size was similar to that of authentic dihydrofolate reductase.