Fig. 1. The TMD of Fis1 is sufficient for mitochondrial targeting. (A) Schematic representation of the GFP-Fis1(TM) protein. (B) Mitochondria (M) were purified via sucrose gradient from wild-type yeast cells or from cells transformed with a vector encoding GFP-Fis1(TM). The post mitochondrial fraction was further separated by differential centrifugation into ER fraction and cytosol (C). Proteins were subjected to SDS-PAGE and immunocytochemistry with antibodies against the GFP moiety, a control marker protein for the cytosol (Bmh1), a control ER marker protein (Erv2) and the mitochondrial outer-membrane protein Tom20.