Immunoprecipitation experiments

Immunoprecipitations (IPs) of POLG, and TFAM were performed by covalently coupling anti-POLG antibody produced in rabbit (Millipore, #ABC462), or anti-TFAM antibody (ProteinTech, #19998-1-AP) onto an amine-reactive resin (Pierce Co-IP kit, catalog no. 26149), following the manufacturer’s instructions. Mitochondrial lysates were incubated with the beads overnight at 4°C and then washed extensively with lysis buffer I. Bound proteins were eluted with tris-glycine (pH 2.8) for 10 min at 4°C. Aliquots corresponding to 20 to 30% of mitochondrial lysates were run alongside the IP fractions onto the gels as inputs.