Mitochondria are endosymbiotic organelles that serve as key hubs for apoptotic regulation, metabolism, and cellular signaling in eukaryotic cells. Over 99% of the ~1500 mitochondrial proteins are encoded in the nuclear genome and depend on specific targeting signals to direct them from the site of synthesis in the cytosol to the appropriate subcompartment. Proper mitochondrial function depends on a process called proteostasis, which ensures that functional proteins are in the right location at the right concentration at the right time. Membrane proteins present unique challenges to the proteostasis network as they must be targeted to the correct membrane and overcome substantial thermodynamic barriers to enter and exit the lipid bilayer, all while avoiding the formation of potentially toxic aggregates in the cytosol. Failures in proteostasis are associated with many neurodegenerative diseases, whereas cancer cells are acutely dependent on robust proteostasis networks to counteract the protein imbalances caused by aneuploidy and dysregulated protein synthesis.
Despite the clear physiological importance, our mechanistic understanding of mitochondrial proteostasis is remarkably incomplete. My lab addresses this critical knowledge gap by focusing on three questions: (1) How do quality control factors discriminate between bona fide substrates and functional proteins in a complex cellular environment, including the lipid bilayer; (2) once a substrate is recognized, what are the downstream steps that lead to resolution of proteotoxic stress; and (3) how can we leverage the resulting mechanistic insights to develop therapeutic interventions in cancer and neurodegenerative disease? My lab addresses these important questions using an array of techniques, including: in vitro reconstitution, structural biology, and cell biology.
Onwunma, J., Binsabaan, S., Allen, S.P., Thanthirige, S.R., Gaur, D., Sankaran, B., & Wohlever, M.L. (2026) ALS mutations disrupt self-association between the Ubiquilin STI1 hydrophobic groove and internal placeholder sequences. EMBO J. 45(8), 2694-2711. https://pubmed.ncbi.nlm.nih.gov/41862640/
Gaur, D., Acquaviva, B., Smith, B., Walker, N., Walter, I., & Wohlever, M.L. (2025) Linked dimers of the AAA+ ATPase Msp1 reveal energetic demands and mechanistic plasticity for substrate extraction from lipid bilayers. FEBS Letters. 600, 83-98. https://pubmed.ncbi.nlm.nih.gov/41084341/
Fresenius, H. L., Gaur, D., Smith, B., Acquaviva, B., & Wohlever, M. L. (2025) Lipid bilayer properties govern substrate engagement and extraction by the AAA+ ATPase Msp1. Journal of Biological Chemistry. 301, 110614. https://pubmed.ncbi.nlm.nih.gov/40840625/
Gaur, D. & Wohlever, M. L. (2025) A suite of pre‐assembled, pET28b‐based Golden Gate vectors for efficient protein engineering and expression. Protein Sci. 34, e70106. https://pubmed.ncbi.nlm.nih.gov/40130802/
Walter, I. R., Smith, B. A., Castanzo, D. & Wohlever, M. L. (2025) Overcoming Fluorescence Loss in mEOS-based AAA+ Unfoldase Reporters Through Covalent Linkage. Protein Expression & Purification 232, 106724. https://pubmed.ncbi.nlm.nih.gov/40306474/
Winter J.M. Fresenius, H.L. Cunningham, C.N. Wei, P. Keys, H.R. Berg, J.A. Bott, A.J. Yadav, T. Ryan, J.A. Sirohi, D. Tripp, S.R. Barta, P. Agarwal, N. Letai, A. Sabatini, D.M. Wohlever, M.L. Rutter, J. (2022) Collateral deletion of the mitochondrial AAA+ ATPase ATAD1 with PTEN sensitizes cancer cells to proteasome dysfunction. Elife 11, 382860. https://pubmed.ncbi.nlm.nih.gov/36409067/
