Visualization of subcellular NAD pools and intra-organellar protein localization by poly-ADP-ribose formation.
Cellular and molecular life sciences : CMLS
confidence
Key findings
Molecular tool using PARP1 to visualize subcellular NAD pools and protein localization; no clinical/biological endpoints reported.
View source on PubMed (PMID 19902144) ↗
- Sample size
- Not reported
- Population
- In vitro cellular model (human PARP1 targeting)
- Dosing
- Not reported
- Duration
- Not reported
- Route
- Not reported
- Blinding
- not_reported
- Controls
- none
- Drug class
- coenzyme
Full abstract
Poly-ADP-ribose polymerases (PARPs) use NAD(+) as substrate to generate polymers of ADP-ribose. We targeted the catalytic domain of human PARP1 as molecular NAD(+) detector into cellular organelles. Immunochemical detection of polymers demonstrated distinct subcellular NAD(+) pools in mitochondria, peroxisomes and, surprisingly, in the endoplasmic reticulum and the Golgi complex. Polymers did not accumulate within the mitochondrial intermembrane space or the cytosol. We demonstrate the suitability of this compartment-specific NAD(+) and poly-ADP-ribose turnover to establish intra-organellar protein localization. For overexpressed proteins, genetically endowed with PARP activity, detection of polymers indicates segregation from the cytosol and consequently intra-organellar residence. In mitochondria, polymer build-up reveals matrix localization of the PARP fusion protein. Compared to presently used fusion tags for subcellular protein localization, these are substantial improvements in resolution. We thus established a novel molecular tool applicable for studies of subcellular NAD metabolism and protein localization.