# SUMOylated Golgin45 associates with PML-NB to transcriptionally regulate lipid metabolism genes during heat shock stress

## TL;DR

Golgin45, a Golgi protein, becomes SUMOylated during heat stress and interacts with PML to regulate lipid metabolism genes.

## Contribution

This study reveals a novel role for SUMOylated Golgin45 in transcriptional regulation of lipid metabolism during heat shock stress.

## Key findings

- Golgin45 is SUMOylated by SUMO1 under normal conditions and by SUMO3 during heat shock.
- SUMOylated Golgin45 interacts with PML to regulate lipid metabolism genes during heat stress.
- A SUMO-deficient Golgin45 mutant inhibits PML-NB formation and suppresses gene transcription.

## Abstract

Golgin tethers are known to mediate vesicular transport in the secretory pathway, whereas it is relatively unknown whether they may mediate cellular stress response within the cell. Here, we describe a cellular stress response during heat shock stress via SUMOylation of a Golgin tether, Golgin45. We found that Golgin45 is a SUMOylated Golgin via SUMO1 under steady state condition. Upon heat shock stress, the Golgin enters the nucleus by interacting with Importin-β2 and gets further modified by SUMO3. Importantly, SUMOylated Golgin45 appears to interact with PML and SUMO-deficient Golgin45 mutant functions as a dominant negative for PML-NB formation during heat shock stress, suppressing transcription of lipid metabolism genes. These results indicate that Golgin45 may play a role in heat stress response by transcriptional regulation of lipid metabolism genes in SUMOylation-dependent fashion.

Golgin45, a Golgi structural protein, is heavily SUMOylated and heat shock stress increases Golgin45 SUMOylation modified by SUMO3 and promotes its inclusion into PML-NBs to transcriptionally regulate lipid metabolism genes.