Michael J. Ragusa
Associate Professor
Appointments
Associate Professor of Chemistry
Area of Expertise
structural biology,
biochemical reconstitution,
peripheral membrane proteins,
autophagy,
membrane remodelling
Biography
To maintain cellular homeostasis long-lived and toxic cellular components must be degraded. Due to their size, large protein aggregates and long-lived organelles are completely inaccessible to the proteasome, the major protein degradation machinery in the cell. As such, cells have evolved autophagy, a process in which double membrane vesicles engulf cytoplasmic material and target it to the vacuole or lysosome for degradation. The sequestering of autophagic cargo was predominantly thought of as a non-selective process. However, it is now clear that the selection of certain autophagic cargo including mitochondria, peroxisomes, lipid droplets, large protein aggregates and intracellular pathogens can occur through a separate process termed selective autophagy. Defective selective autophagy has been correlated with tumorigenesis, chronic infection and neurodegenerative disease. We are using cell biology, structural biology and biochemical reconstitution to dissect the molecular mechanisms governing this critical pathway. Gaining an understanding of the molecular mechanisms of selective autophagy will allow for the development of novel therapeutics for the treatment of cancer, neurodegeneration, and infectious diseases.
Education
B.S. Siena College
Ph.D. Brown University
Taught Courses
Publications
Andhare, D., Katzenell, S., Najera, S. I., Mauras, S. C., Bauer, K. M., & Ragusa, M. J. Reconstitution of autophagic-like membrane tethering reveals that Atg11 can bind and cluster vesicles on cargo mimetics. Autophagy 2025; 1–20.
Hawkins WD#, Leary KA#, Andhare D, Popelka H, Klionsky DJ*, Ragusa MJ*. Dimerization-dependent membrane tethering by Atg23 is essential for yeast autophagy. Cell Reports 2022; 39(3):110702. #Equal contribution *Corresponding authors.
Reinhart EF, Litt NA, Katzenell S, Pellegrini M, Yamamoto A, Ragusa MJ. A highly conserved glutamic acid in ALFY inhibits membrane binding to aid in aggregate clearance. Traffic 2021; 22: 23-37.
Margolis HK#, Katzenell S#, Leary KA, Ragusa MJ. The third coiled coil domain of Atg11 is required for shaping mitophagy initiation sites. Journal of Molecular Biology 2020; 432: 5752-5764. #Equal contribution.
Popelka H, Damasio A, Hinshaw JE, Klionsky DJ, Ragusa MJ. Structure and function of yeast Atg20, a sorting nexin that facilitates autophagy induction. Proceedings of the National Academy of Sciences 2017; 114:E10112-E21.
MJ Ragusa*, RE Stanley*, JH Hurley. Architecture of the Atg17 Complex as a Scaffold for Autophagosome Biogenesis. Cell 2012; 151: 1501-1512. *These authors contributed equally to the work
S Baskaran, MJ Ragusa, E Boura, JH Hurley. Two-Site Recognition of Phosphatidylinositol 3-Phosphate by PROPPINs in Autophagy. Molecular Cell 2012; 47: 339-348.
B Dancheck*, MJ Ragusa*, M Allaire, AC Nairn, R Page, W Peti. Molecular Investigations of the Structure and Function of the Protein Phosphatase 1:Spinophilin:Inhibitor-2 Heterotrimeric Complex. Biochemistry 2011; 50: 1238-1246. *These authors contributed equally to the work
MJ Ragusa, M Allaire, AC Nairn, R Page, W Peti. Flexibility in the PP1:spinophilin holoenzyme. FEBS Letters 2011; 585: 36-40.
MJ Ragusa, B Dancheck, DA Critton, AC Nairn, R Page, W Peti. Spinophilin directs protein phosphatase 1 specificity by blocking substrates binding sites. Nature Structural and Molecular Biology 2010; 17: 459-464.
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