The Characterization of a Putative Perilipin 5 Splice Variant

Abstract

Lipid droplets, or LDs, are very important and dynamic organelles in cells. LDs are stores of fat for use in metabolism, membrane construction, and signaling. Dysfunction of lipid droplet formation or breakdown can lead to many health risks, such as atherosclerosis and diabetes. Lipid droplet regulation occurs primarily via a dynamic and complex coat of proteins on the surface of the droplet including the perilipins. Perilipin‐5 is a member of the perilipin family of lipid droplet coat proteins and is found primarily in tissues that break down fats for energy, such as heart, liver, and skeletal muscle. We hypothesize that the perilipin 5 gene is differentially spliced into messages that code for different forms of the protein, all of which play roles in lipid metabolism. This work seeks to characterize a novel 35 kDa protein found in mouse which we have termed perilipin‐5B. Western blotting with an anti‐amino terminal perilipin 5 specific antibody showed that perilipin‐5B is expressed in the same tissues as perilipin 5. RT‐PCR showed that multiple messages exist that include intron 8 of the perilipin‐5 gene. Other splice variants of this gene may exist which may give rise to other proteins. Together, these data indicate that perilipin‐5B is a splice variant of perilipin‐5 found in oxidative tissues.