SUMOylation is a post-translational modification that attaches a ubiquitin-like modifier to target proteins and plays a number of roles throughout the cells, including transcriptional regulation and cellular stress response, etc. We have recently reported that a Golgi structural protein, Golgin45, is subjected to Tankyrase1-dependent poly (ADP-Ribosyl)ation, resulting in dynamic regulation of Golgin45 protein and membrane trafficking of glycosylating enzymes at the Golgi. However, exact mechanism that modulates Tankyrase activity on Golgin45 remained elusive. Here, we report that Golgin45 is a SUMOylated protein, and heat shock significantly increases Golgin45 SUMOylation, concomitantly leading to reduced PARylation. Importantly, while PML is required for Golgin45 SUMOylation by SUMO3, over-expression of a SUMOylation-deficient Golgin45 mutant inhibits the formation of PML-NBs under heat shock, revealing a role of SUMOylated Golgin45 in PML-NB formation in the nucleus. These results provide a new insight into stress-induced inter-organelle communications between the Golgi and the nucleus.