Parkinson disease (PD) is a relatively common neurodegenerative disorder, affecting 1-2% of the world's population over the age of 65 years. About 5-10% of PD cases are inherited, and mutations in the Parkin gene are a common cause of familial PD. Michael Sack and colleagues, at the National Institutes of Health, Bethesda, have now identified a new function for the protein templated by the Parkin gene, it regulates fat uptake from the blood by liver cells and thereby fat levels in the blood. Furthermore, they determine that it does this by regulating the level of expression of the fat transporter CD36 on liver cells. Future studies will determine whether perturbations in this function of parkin contribute to the development of PD caused by mutations in the Parkin gene.

As noted in an accompanying commentary, by Nada Abumrad, at Washington University School of Medicine, St Louis, and Darren Moore, at Ecole Polytechnique Fédérale de Lausanne, Switzerland, the additional observation of Sack and colleagues that levels of parkin protein are increased in mice fed a high-fat diet, provides support for the emerging idea that dietary fat intake can impact susceptibility to PD.