The long-term goal of this project is to elucidate the molecular mechanism by which autophagy receptors effect selective autophagy in both normal and disease conditions. Autophagy is a process of non-selective cytoplasmic degradation that is required for cell survival during periods of starvation or stress (termed bulk autophagy), as well as for the selective degradation of protein aggregates, damaged organelles, and other large targets that otherwise accumulate and cause disease (selective autophagy). In nearly all cases, the induction of autophagy requires the activation of a dedicated kinase, Atg1, that is conserved from yeast (Atg1) to man (ULK1 and ULK2). Neither how ULK1/2 are activated, nor how phosphorylation of ULK1/2 substrates enables autophagy induction is well understood. The goal of this proposal is to take an autophagy-receptor- centric approach to understanding selective autophagy in mammalian systems. Specifically, in Aim 1, I will biochemically characterize the role of autophagy receptors in ULK1/2 activation. I will then determine the effect of receptor mutations associated with human disease.
In Aim 2, I will use CRISPR/Cas9 technology to screen for novel modulators of selective autophagy in mammalian cells, including screens for suppressors of disease- associated alleles. These studies will identify potential therapeutic targets for autophagy-associated diseases.
In Aim 3, I will use a novel cell free assay for ULK1/2 activity to identify substrates of these autophagy kinases and determine the mechanism by which ULK1/2 activation by receptors drives selective autophagy. Collectively, my combined approaches will reveal conserved principles of autophagy induction and, ultimately, inform our understanding of autophagy dysregulation in various disease states. During the early stage of this award, I will gain valuable technical skills, including in mammalian tissue culture, CRISPR screening and mass spectrometry, that will enable me to develop a unique research program. Under the mentoring of my formal advisory committee, I will develop important soft skills, such as grant writing, presentation skills and lab leadership. This combination of training, support and career mentoring will be instrumental in my transition to independence as a tenure-track faculty at a leading institution.
Public Health Relevance: The dysregulation of autophagy is associated with cancer, neurodegeneration and aging, but the mechanistic details behind these relationships are poorly understood. The proposed research will elucidate the role of autophagy receptors in selective autophagy, focusing on the effects of disease- associated mutations in autophagy receptors. A thorough understanding of autophagy induction mechanisms will inform our understanding of how autophagy becomes dysregulated in disease and guide therapeutic attempts to ameliorate these deficiencies.