Researchers world-wide are focused on clearing the toxic mutant Huntingtin (HTT) protein that leads to neuronal cell death and systemic dysfunction in Huntington's disease (HD), a devastating, incurable, progressive neurodegenerative genetic disorder. Scientists in the lab of Buck Institute Professor Linda Ellerby, PhD, lab have found that the targeting the protein called FK506-binding protein 51 (FKBP51) promotes the clearing of those toxic proteins via autophagy, a natural process whereby cells recycle damaged proteins and mitochondria and use them for nutrition. In an article published online on May 24, 2021 in Autophagy, researchers showed that FKBP51 promotes autophagy through a new mechanism that could avoid worrisome side effects associated with rapamycin, an immune-suppressing drug which also extends lifespan in mice. They show that both rapamycin and the small pharmacological inhibitor of FKBP51, SAFit2, protect HD neurons but that the mechanisms of the two drugs are distinct. The open-access Autophagy article is titled “Modulating FKBP5/FKBP51 and Autophagy Lowers HTT (Huntingtin) Levels.”