Characterization of a Perilipin‐5 Splice Variant

Abstract

Perilipin‐5, the newest member of the perilipin family of lipid droplet proteins, has been found to be expressed in oxidative tissues, specifically heart, brown adipose tissue, and fasted liver. This work seeks to characterize a novel splice variant for perilipin‐5 we have termed Perilipin‐5B. Western blots indicate that the protein, of approximately 35 kDa, is present in C2C12 cultured myoblasts and in heart and liver tissue from fed and fasted mice. Highest levels of the protein were present in heart tissue from fed mice. Analysis of murine genomic DNA sequences reveals stop codons found in the introns between exons 7 and 8 and 8 and 9, either of which could give rise to a protein of approximately 35 kDa. Other members of the PAT family, such as Perilipin‐1, have multiple protein products arising from splice variants. The function of perilipin‐5B is yet unknown, but the interesting observation that it is found primarily in fed heart tissue suggests that it plays a role in the oxidation of the lipid droplet. Knowledge of this protein's function will give a more complete picture as to the overall mechanism of lipid storage and metabolism.