Fig. 5. Periplakin colocalises with mitochondira. (A) Confocal immunostaining for periplakin. MCF-7 cells were pre-incubated with Mitotracker and co-immunostained for periplakin using the anti-periplakin 5117 antibody (upper panel). Similar staining was observed with the other antibodies (5118, 7445 and 7446) and with affinity-purified 5117. No staining was observed using pre-immune serum from the rabbits (5117 and 5118) used for immunization with GST-c-ppl. MCF-7 cells were transiently transfected with HA-Ppl and immunostained for HA-Ppl using the HA antibody and for cytochrome c (lower panel). Bars, 10 µm. (B/C) Periplakin is found in mitochondrial fractions. (B) COS-7, MCF-7/FR and Rat-1 cells were fractionated using a Percoll gradient and the fractions were analysed by western blotting using anti-periplakin 5117, anti-PKB, anti-cox4 and anti-MAPK antibodies. (C) MCF-7/FR and Rat-1 cells were fractionated using the mitochondria affinity purification protocol. Fractions were analysed by immunoblotting, using the same antibodies as in B.