Identification of proteins associated with the human mitochondrial degradosome

The human mitochondrial degradosome is a complex of the ribonuclease PNPase (Q8TCS8, encoded by PNPT1 gene) and RNA helicase SUV3 (Q8IYB8, encoded by SUPV3L1 gene). The aim of the project was to identify proteins which co-purify with both subunits of the degradosome. To this end we used human 293 cells stably expressing hSuv3 or PNPase with a C-terminal TAP tag or TAP tag fused to a mitochondria targeting sequence (control bait) (cell lines are described in details in (PMID: 19864255). Mitochondria were isolated from the cells, lysed and the protein extracts were subjected to affinity chromatography. Co-purified proteins were identified by mass spectrometry and their amounts were quantified by a label-free approach (MaxQuant). These experiments are part of the project “Dedicated surveillance mechanism controls G-quadruplex forming non-coding RNAs in human mitochondria”.