Poly(ADP-ribose), adherens junctions, vinculin and the actin cytoskeleton: Current evidence, future perspectives and implications

Poly(ADP-ribose) (PAR) is a highly negatively charged polymer. PAR is synthesized by poly(ADP-ribose) polymerases (PARPs) and is involved in the assembly and stabilization of macromolecular complexes. Here, the presence and putative roles of poly(ADP-ribosyl)ation (PARylation) associated to adherens junctions (AJ) and the actin cytoskeleton in epithelial and Schwann cells, is reviewed. The hypothesis generated by analogy, stating that PAR is associated to AJ in other cell types, is postulated. According to this hypothesis, PAR associated to puncta adherentia in chemical synapses would participate in plasticity, learning and memory. In turn, PAR associated to fascia adherens in cardiomyocytes, would affect heart beating. PARP inhibitors are currently under development and clinical testing. Basic research in different tissues will probably influence their clinical uses.