Mitochondria are devoid of poly(ADP?ribose)polymerase?1, but harbor its product oligo(ADP?ribose)

There are conflicting data about localization of poly(ADP-ribose)polymerase-1 and its product poly(ADP-ribose) in mitochondria. To finally clarify the discussion, we investigated with biochemical cell biological methods potential presence polymerase-1 these organelles. Our show that endogenous overexpressed poly(ADP-ribose)polymerase 1 is only localized to nucleus a clear exclusion cytosolic compartments. In addition, highly purified mitochondria devoid nuclear contaminations do not contain poly(ADP-ribose)polymerase-1. Although no enzyme detectable mitochondria, shorter variant present, associated specifically small subset mitochondrial proteins as revealed by immunoprecipitation protein fingerprint analysis. These located at key-points Krebs-cycle, chaperones involved functionality quality-control, RNA-binding important for transcript stability, respectively. Of note, despite fact especially own major target modification, could detect this mass spectrometry suggests new way targeted nuclear-mitochondrial signaling, mediated poly(ADP-ribosyl)ation dependent on