Characterization of a novel short‐form of perilipin‐5

Abstract

The perilipins are a family of five interrelated genes with conserved sequences. Perilpin‐5 is expressed most strongly in oxidative tissues such as heart and fasting liver and has been shown to interact with both the lipase ATGL and the ATGL co‐activator CGI‐58 (ABDH‐5). Perilipin‐5 has recently been shown to localize to the lipid storage droplet and a small lipoprotein‐like structure found in the cytosol. Using western blotting, we have identified a short form of perilipin‐5 we have termed perilipin‐5B. This 35 kDa protein is found in liver, heart, and c2c12 myoblasts. Immunofluorescence of c2c12 myoblasts shows staining in cytosol and lipid droplets, as well as some other membranous structures. Analysis of murine genomic DNA sequences reveals stop codons found in the introns between exons 7 and 8 and 8 and 9, any of which could give rise to a protein of approximately 35 kDa. Interestingly, many of the functions ascribed to perilipin‐5 have been attributed to the carboxy‐terminus of the protein, which would be missing in this proposed truncation. Support for this research provided by the Chemistry Department of Otterbein University and the Bert and Jane Horn endowed student research fund in the sciences.