Advanced tools for the analysis of protein phosphorylation in yeast mitochondria

The biochemical analysis of protein phosphorylation in mitochondria lags behind that of cytosolic signaling events. One reason is the poor stability of many phosphorylation sites during common isolation procedures for mitochondria. We present here an optimized, fast protocol for the purification of yeast mitochondria that greatly increases recovery of phosphorylated mitochondrial proteins. Moreover, we describe improved protocols for the biochemical analysis of mitochondrial protein phosphorylation by Zn2+-Phos-tag electrophoresis under both denaturing and - for the first time - native conditions, and demonstrate that they outperform previously applied methods.