A thematic review series continues in the July issue of the Journal of Lipid Research with an article titled “The proteomics of lipid droplets: structure, dynamics and functions of the organelle conserved from bacteria to humans.” The manuscript is part of the series being coordinated by Karen Reue of the University of California, Los Angeles, an editorial board member of the journal.
In the July review, Li Yang and colleagues from the Chinese Academy of Sciences explore how proteomic studies on lipid droplets in a wide range of organisms — from one-celled bacteria to higher-order mammals — provide evidence that the function of some of the compounds contained in these droplets has been conserved, despite millions of years of evolution.
Several important functional groups of proteins seem to be consistently present and represented. These include enzymes that synthesize lipids, proteins involved in molecular trafficking across membranes, signaling proteins and proteins associated with protein degradation. Both proteomics and cell biology data suggest all organisms can hold neutral lipids in lipid droplets. But lipid droplets, once guessed to be inert lipid storage units in the simplest of organisms, now appear to be highly evolved and functional cellular organelles in more complex creatures.
While structural proteins of lipid droplets may vary greatly from organism to organism, they all have in common certain properties that tag and target them for these specialized organelles. Further proteomic analyses certainly are warranted, as lipid droplets have been linked to the development of certain metabolic diseases. They also have great potential in the research into neutral lipid-derived products that could have energy (biofuel), food and medication applications.
Mary L. Chang (email@example.com) is managing editor of the Journal of Lipid Research and coordinating journal manager of the journal Molecular & Cellular Proteomics.