Characterization of a Shortened Form of the Perilipin 5 Protein

Abstract

Many modern health issues arise from aberrant lipid metabolism, among these are type II diabetes and non‐alcoholic fatty liver disease. One commonality these diseases share is neutral lipid metabolism and storage. Regulation of neutral lipid metabolism is of vital importance in the body, and among the proteins responsible for such regulation are the perilipins. Perilipins are a family of conserved proteins that are found on the surface of lipid storage droplets and play a central role in the regulation of cellular neutral lipid metabolism. Perilipin 5, specifically, is expressed in tissues with a high capacity for fatty acid oxidation such as cardiac muscle, oxidative muscle, and fasting liver. Using western blotting and reverse transcriptase PCR, we have identified a splice variant of perilipin 5 which has been termed perilipin 5b. This shortened form of the protein retains the amino terminal 35 kDa of the protein but lacks the 4‐helix bundle found in the C‐terminus. Based on the reports in the literature, this protein would lack the carboxy terminal domains reported to be necessary for interactions with lipases and other proteins but would retain serine 155 that is requisite for PKA phosphorylation and translocation to the nucleus. We have constructed a carboxy terminal truncation of perilipin 5 and are expressing it in CHO cells to further define the function of this protein. When compared with CHO cellular expression of perilipin 5, 5b appears to have a higher number of smaller lipid droplets per cell. Collectively these data indicate that perilipin 5b plays a role in lipid storage, but its specific function of this shortened form is still unknown.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.