ERLIN1 may be involved in DHRS1-induced Change in Lipid Droplet Morphology in HeLa Cell

Dehydrogenase/reductase (SDR family) member1, DHRS1, a member of the conserved short chain dehydrogenase/reductase (SDR) superfamily, has been identified in lipid droplets proteome of different cells and tissues. However, until now, little is known about the potential role of DHRS1 on the lipid droplet (LD). Here, we report that DHRS1 localized to the lipid droplet in Huh7 and HeLa cells and ectopic expression of DHRS1 in HeLa cell induced a significant change in the lipid droplet morphology resulting in nearly 2 fold increase both in lipid droplet size and total triacylglycerol level independent of oleic acid treatment. DHRS1 interacted with ERLIN1, a non-caveolae lipid raft-like domain marker, in HeLa cell and ERLIN1 deficient HeLa cells displayed no detectable change in LD morphology. Although ectopic expression of DHRS1-GFP fusion protein in ERLIN1 deficient HeLa cells resulted in fewer GFP-labeled ring structures relative to WT HeLa cell; thus suggesting that ERLIN1 may be involved in regulating DHRS1 protein turnover. Taken together, these data showed that DHRS1 localized to the LD and induced a significant change in LD morphology which may be regulated by ERLIN1.