Plasmid construction and transfection

The cDNA sequences encoding ATP5B or DRP1 were amplified by PCR using the oligonucleotide primers (Genomics, Hsinchu, Taiwan). The amplified fragments were cloned into a pPAGFP-N1 vector (RRID: Addgene_11909) or pCMV-HA-N vector (Clontech Cat# 635690), respectively. MOM-GFP plasmid containing mitochondrial targeting sequence of Tom70 fused to pEGFP-N1 vector was a gift from Josef Kittler (RRID: Addgene_127633)^{95 (link)}. Mitochondrial targeting sequence from subunit VIII of human cytochrome C oxidase was amplified from DsRed2-Mito-7, a gift from Michael Davidson (RRID: Addgene_55838) by PCR, and cloned into pEGFP-N1 vector backbone to be Mito-GFP plasmid. All clones were verified by sequencing (Genomics). The Escherichia coli DH5α strain was used as the competent cell for the transformation of these constructs. The QIAGEN Plasmid Midi Kit (QIAGEN Cat#12143) was used for the purification of plasmids, and the concentration of the purified plasmids was determined using the NanoDrop ND-1000 (NanoDrop Technologies, Montchanin, DE). Plasmids were transfected into cells using jetPRIME (Polyplus-transfection Cat#114-15) according to the instructions provided by the manufacturer, and the transfected cells were incubated for at least 24 h before further experiments.