Molecular signaling and bioenergetics

Poly-ADP-ribose-assisted NAD detection

Poly-ADP-ribose polymerases (PARPs) use NAD+ to catalyze the synthesis and transfer onto acceptor proteins of long, branched polymers of ADP-ribose (PAR). PAR-specific antibodies allow for immunodetection of this reversible covalent protein modification. Targeted expression of the catalytic domain poly-ADP-ribose polymerase 1 (PARP1cd) in membrane-bounded organelles is our experimental tool to visualize and manipulate NAD availability at the subcellular level.

Subcellular NAD
PAR immunocytochemistry in response to compartment-specific expression of the catalytic domain of poly-ADP-ribose polymerase 1 (PARP1cd) demonstrates NAD availability in mitochondria, peroxisomes, the endoplasmic reticulum and the Golgi complex. Absence of PAR-immunoreactivity upon PARP1cd expression in the cytosol and the nucleus may be due to strong PAR-degrading activities in these compartments.
from VanLinden et al. (2017), Methods Mol. Biol. 1608