CELL BIOLOGY SYMPOSIUM: Imaging the organization and trafficking of lipolytic effectors in adipocytes

The storage and mobilization of lipid energy are central functions of adipocytes. Lipid energy is stored as triglyceride in lipid droplet structures that are now recognized as bona fide organelles and whose functions are greatly influenced by members of the perilipin family of lipid droplet scaffolds. Recent work indicates that the signaling events underlying fatty acid mobilization involve protein trafficking to a specialized subset of lipid droplets. Furthermore, the core lipolytic machinery is composed of evolutionarily conserved proteins whose functions are conserved in avian and mammalian production species. Lipolysis affects many aspects of animal nutrition and physiology, which can have an important influence on growth efficiency, lactation, and meat quality. This review focuses on recent research that addresses the organization and trafficking of key players in hormone-stimulated lipolysis, and the central role of perilipin1A in adipocyte lipolysis. The review emphasizes recent work from the laboratories of the authors that utilizes imaging techniques to explore the organization and interactions among lipolytic effectors in live cells during lipolytic activation. A mechanistic understanding of lipolysis may lead to new strategies for promoting human and animal health.