Subcellular distribution of various PINK1 mutants in Hela cells by fractionation. A) PINK1 MLS-GFP localizes to the mitochondria and is partially sensitive to proteinase K digestion. B) mito-GFP localizes to the mitochondria and is not digested by proteinase K. C) Overexpression of wildtype PINK1-flag displays dual localization for all forms of PINK1. D) Immt-Δ151 PINK1 localizes to the mitochondria and is sensitive to proteinase K digestion. E) mito-Δ151 PINK1 localizes equally in both cytosol and mitochondria, where the mitochondria fraction is not digested by proteinase K. F) Δ90-110 PINK1 mostly localizes to mitochondrial fraction with a small portion of cleaved form redistributed to the cytosolic fraction. G) Δ151 PINK1 localizes mainly in the cytosol with a small pool in the mitochondria. H) Drosophila PINK1-flag (DmPINK1) transfected in Hela cells also distributed to both cytosolic and mitochondrial fractions, similar to human PINK1. ATP5A, the α-subunit of ATP synthase, marks the mitochondria. p38 MAPK marks the cytosol.