Figure 1. Pet309 interacts with the COX1 mRNA. (A) Mitochondria were solubilized with dodecyl maltoside and Pet309-HA or untagged Pet309 were subjected to immunoprecipitation with anti-HA antibody. One fourth of the immunoprecipitate (IP) and the supernatant fraction representing non-bound proteins (S) were separated by SDS-PAGE and transferred to a PVDF membrane for western blot. The membrane was probed with anti-HA antibody (HA), with anti-Cox1 antibody, and with anti-citrate synthase antibody (CS) as a negative control for interaction. The total fraction (T) represents 5% of the mitochondrial extract used for immunoprecipitation. (B) RNA was extracted from the total (T), immunoprecipitate (IP) and supernatant (S) fractions. Each fraction was divided in two, and cDNA was prepared in the presence (+) or absence (-) of reverse transcriptase (RT) using primers for the COX1, COX3, ATP8, ATP6 or VAR1 5′-UTRs. The (-) RT lanes represent a negative control for DNA contamination. The PCR products were run on an agarose gel, and for clarity, the gel pictures were color inverted. The circle (•) indicates bands due to primer dimers. (C) The agarose gels from B) were transferred to a Nylon membrane and the portion of the membrane with the COX1 and COX3 amplification products (*) were hybridized with probes for COX1 and COX3. This experiment represents one of three independent repeats.