Ryu, HyunjuFuruta, MaikoKirkpatrick, DonaldGygi, StevenAzuma, Yoshiaki2011-10-192010Ryu, Hyunju, Maiko Furuta, Donald Kirkpatrick, Steven P. Gygi, and Yoshiaki Azuma. 2010. PIASy-dependent SUMOylation regulates DNA topoisomerase IIα activity. The Journal of Cell Biology 191(4): 783-794.0021-9525http://nrs.harvard.edu/urn-3:HUL.InstRepos:5265976DNA topoisomerase IIα (TopoIIα) is an essential chromosome-associated enzyme with activity im- plicated in the resolution of tangled DNA at cen- tromeres before anaphase onset. However, the regulatory mechanism of TopoIIα activity is not understood. Here, we show that PIASy-mediated small ubiquitin-like modifier 2/3 (SUMO2/3) modification of TopoIIα strongly inhibits TopoIIα decatenation activity. Using mass spectrometry and biochemical analysis, we demonstrate that TopoIIα is SUMOylated at lysine 660 (Lys660), a residue located in the DNA gate domain, where both DNA cleavage and religation take place. Remarkably, loss of SUMOylation on Lys660 eliminates SUMOylation-dependent inhibition of TopoIIα, which indicates that Lys660 SUMOylation is critical for PIASy-mediated inhibition of TopoIIα activ- ity. Together, our findings provide evidence for the reg- ulation of TopoIIα activity on mitotic chromosomes by SUMOylation. Therefore, we propose a novel mechanism for regulation of centromeric DNA catenation during mitosis by PIASy-mediated SUMOylation of TopoIIα.en-USJournal Article2011-10-1910.1083/jcb.201004033