Figure 3.
Aster assembly trigged by pADPr on beads. Magnetic beads coated with PARP-5a lacking catalytic activity (PD-PARP-5a) or PARP-5a decorated with pADPr (PARP-5a-pADPr) were added to concentrated mitotic lysate containing Alexa 594 tubulin and 1 μM ADP-ADHP to inhibit PARG activity. Note that pADPr-coated beads induced assembly of microtubule asters. Addition of extra NAD+ (+250 μM NAD+ and + 500 μM NAD+) to the lysate to promote additional pADPr polymerization increased the density of asters and the density of microtubules within them. Microtubule appeared not to emanate directly from the pADPr-coated beads; rather they assembled into asters that associated laterally with beads.