Allyson O'DonnellAssistant Professor
Bayer School of Natural and Environmental Sciences
Department of Biological Sciences
Education:Research Assistant Professor, University of Pittsburgh, 2012-2014
Postdoctoral Fellow, University of California at Berkeley, 2010-2012
Postdoctoral Fellow, Stanford University, 2004-2010
Ph.D., Dalhousie University, 2004
M.S., University of New Brunswick, 1998
B.S. (Honors), University of New Brunswick, 1996
Dr. Allyson O'Donnell is an Assistant Professor in the Department of Biological Sciences at Duquesne University. She is also a member of the American Society for Cell Biology and a mentor for the Science Research outreach program at Taylor Allderdice High School.
Dr. O'Donnell is one of the founding members of the Women in Science at Duquesne University (WIS@DU). Website: www.duq.edu/WISDU.
She is also a member of the Center for Protein Conformational Diseases at the University of Pittsburgh. Website: http://www.proteindiseasecenter.pitt.edu/about-our-center.
Dr. O'Donnell received her B.S. degree in Biochemistry and M.S. degree in Biology from the University of New Brunswick (Canada). During her Masters thesis work she identified genes needed for de novo purine biosynthesis in Drosophila melanogaster and characterized the developmental defects associated with mutations in these genes. Dr. O'Donnell went on to receive her Ph.D. in Biochemistry & Molecular Biology from Dalhousie University (Canada) where she studied the role of the FACT histone chaperone complex in chromatin remodeling..
During her post-doctoral research at Stanford University and the University of California, Berkeley Dr. O'Donnell began her research on a previously unstudied class of protein trafficking adaptors, now referred to as the α-arrestins. Her research has shown that α-arrestins regulate trafficking of G-protein coupled receptors, but also operate in unexpected trafficking pathways, including endosomal recycling and clathrin-independent endocytosis. Using Saccharomyces cerevisiae as a model, she has identified α-arrestin interactions with signaling regulators, cargos and vesicle coat proteins, and has begun to define the molecular mechanisms underlying α-arrestin-mediated trafficking. Her research applies insights gained in yeast to target studies on the relatively unstudied mammalian α-arrestins.
Regulation of Protein Trafficking by α-arrestins
Research Description: In order to survive, cells must selectively target proteins to new intracellular locales in response to environmental change. Trafficking adaptors act at a critical nexus between cell signing and protein trafficking. In particular our research focuses on a little-studied class of trafficking adaptors known as the α-arrestins. Using Saccharomyces cerevisiae as a model system, our research has shown that α-arrestins interact with signaling regulators, including kinases and phosphatases, to selectively direct trafficking of specific transmembrane cargo proteins, presumably by promoting their packaging into vesicles (Figure 1). We are applying insights gained from yeast to initiate studies of mammalian α-arrestins. Current research in the lab focuses on:
1) Delineating the signaling pathways that regulate α-arrestins: Arrestins respond to signaling cues to selectively bind and regulate trafficking of their membrane cargo (Figure 2). Phospho-regulation of α-arrestins is complex, with over 25 phospho-sites on a single α-arrestin. We have identified protein phosphatases and kinases that act as regulatory switches to control α-arrestin-mediated trafficking. Our work suggests that phosphorylation inhibits the endocytic function of α-arrestins while promoting intracellular sorting. In addition, ubiquitination of α-arrestins also has a role in regulating α-arrestin-mediated trafficking, and we are currently mapping α-arrestin ubiquitination sites using mass spectrometry and assessing their impact on trafficking functions.
2) Defining trafficking functions for α-arrestins: While α-arrestins have a well-established role in regulating clathrin-mediated endocytosis (Figure 1), we have expanded their repertoire of function identifying a new role for these adaptors in clathrin-independent endocytosis as well as intracellular sorting of protein cargo. How α-arrestins contribute to these and other new protein trafficking pathways is an area of active investigation in the lab.
3) Identifying new α-arrestin cargos: Using a computational biology approach, we are generating a comprehensive map of α-arrestin-cargo pairs. To date, we have identified many new membrane proteins whose trafficking is regulated by α-arrestins and we will leverage these findings to define α-arrestin-cargo interaction interface.
Prosser, D.C., K. Wrasman, T.K. Woodard, A.F. O'Donnell, and B. Wendland. (2016) Applications of pHluorin for quantitative, kinetic and high-throughput analysis of endocytosis in budding yeast. Journal of Visual Experiments, 116 DOI:10.3791/54587.
Chandrashekarappa, D.G., R.R. McCartney, A.F. O'Donnell, and M.C. Schmidt. (2016) The b submit of yeast AMP-activated protein kinase directs substrate specificity in response to alkaline stress. Cellular Signaling, S0898065568(16):302221-2.
Prosser, D.C., A.E. Pannunzio, J.L. Brodsky, J. Thorner, B. Wendland, A.F. O'Donnell*. (2015) Alpha-arrestins participate in cargo selection for both clathrin-independent and clathrin-mediated endocytosis. Journal of Cell Science, 128(22):4220-34.
O'Donnell, A.F., R. R. McCartney, D. G. Chandrashekarappa, B. Zhang, J. Thorner, and M.C. Schmidt. (2014) 2-Deoxyglucose impairs yeast growth by stimulating Snf1-regulated and α-arrestin-mediated trafficking of hexose transporters 1 and 3 in Saccharomyces cerevisiae. Molecular and Cellular Biology, 35(6):939-55.
C.G. Alvaro, A.F. O'Donnell*, D.C. Prosser, A.A. Augustine, A. Goldman, J. Brodsky, M.S. Cyert, B. Wendland, and J. Thorner. (2014) Specific α-arrestins negatively regulate Saccharomyces cerevisiae pheromone response by down-modulating the G-protein coupled recpetor Ste2. Molecular and Cellular Biology 34(14):2660-81. *Co-first author
Hecht, K.A., A.F. O'Donnell, and J. Brodsky. (2014) The proteolytic landscape of the yeast vacuole. Cellular Logistics 4 (1): e28023.
O'Donnell, A.F., L. Huang, J. Thorner, and M.S. Cyert. (2013) A calcineurin-dependent switch controls the trafficking function of α-arrestin Aly1/Art6. The Journal of Biological Chemistry. 288 (33): 24063-24080
O'Donnell, A.F. (2012) The running of the Buls: Control of permease trafficking by α-arrestins Bul1 and Bul2. Molecular and Cellular Biology 32 (22): 4506-09.
Stevens, J.R., A.F. O'Donnell, T.E. Perry, J.R. Benjamin, C.A. Barnes, G.C. Johnston, and R.A. Singer. (2011) FACT, the Bur kinase pathway, and the histone co-repressor HirC have overlapping nucleosome-related roles in yeast transcription elongation. PLoS One 6 (10): e25644.
Minear, S., A.F. O'Donnell*, G. Giaever, C. Nislow, T. Stearns, and M.S. Cyert. (2011) Curcumin inhibits growth of Saccharomyces cerevisiae through iron chelation. Eukaryotic Cell 10 (11): 1574-81. *Co-first author
Piña, F.J., A.F. O'Donnell, S. Pagant, H.L. Piao, J.P. Miller, S. Fields, E.A. Miller, and M.S. Cyert. (2011) Hph1 and Hph2 are novel components of the Sec63/Sec62 posttranslational translocation complex that aid in vacuolar proton ATPase biogenesis. Eukaryotic Cell 10 (1): 63-71.
O'Donnell, A.F., A. Apffel, R.G. Gardner, and M.S. Cyert. (2010) α-arrestins Aly1 and Aly2 regulate intracellular trafficking in response to nutrient signaling. Molecular Biology of the Cell 21 (20): 3552-3566. (Highlighted publication in MBoC)
O'Donnell, A.F., J.R. Stevens, R. Kepkay, C.A. Barnes, G.C. Johnston, and R.A. Singer. (2009) New mutant versions of yeast FACT subunit Spt16 affect cell integrity. Molecular Genetics and Genomics 282 (5): 487-502.
O'Donnell, A.F., N.K. Brewster, J. Kurniawan, L.V. Minard, G.C. Johnston, and R.A. Singer. (2004) Domain organization of the yeast histone chaperone FACT: the conserved N-terminal domain of FACT subunit Spt16 mediates recovery from replication stress. Nucleic Acids Research 32 (19): 5894-5906.
O'Donnell, A.F., S. Tiong, D. Nash, and D.V. Clark (2000) The Drosophila melanogaster ade5 gene encodes a bifunctional enzyme for two steps in the de novo purine synthesis pathway. Genetics 154 (3): 1239-1253.
- BIOL 647 Advanced Cell & Molecular Biology II
- BIOL 371W Lab II: Cell and Molecular Biology
Spring 2016: BIOL 647 Advanced Cell & Molecular Biology II
Fall 2015: BIOL 115 Advanced General Biology I
Spring 2015: BIOL 313/513 Developmental Biology
Spring 2015: BIOL 647 Advanced Cell & Molecular Biology II
Dr. Allyson O'Donnell was selected for a five-year, NSF Faculty Early Career Development Program Grant, which is awarded to less than 10 percent of all applicants.
The National Science Foundation (NSF) awarded O'Donnell a grant of more than $1 million to explore how cells adapt to stress and changes in their environment by reorganizing existing proteins.
O'Donnell is the third scientist in Duquesne's Bayer School of Natural and Environmental Sciences to receive this prestigious grant since 2008, said Bayer Dean Dr. Philip Reeder. "We're very excited about Dr. O'Donnell's award and the opportunities to expand her research while involving our students and high school partners," he said. "The award not only illustrates the high quality of research at Duquesne, given their highly competitive nature, but confirms the consistent excellence in research and teaching among our faculty."
Photo at right: Dr. Allyson O'Donnell, seated, discusses a sample with her lab team, which includes undergraduate and high school students.
Titled Regulation of Cargo Selection and Ubiquitination by Protein Trafficking Adaptors, O'Donnell's research examines a process called protein trafficking that determines which proteins go where inside the cell. In response to new environments, some proteins may stay in place but others may be carted away and targeted for degradation, which allows for constant remodeling of the cell.
O'Donnell's work focuses on a class of proteins called alpha-arrestins, which are devoted to the selective protein reshuffling that occurs inside the cell in response to environmental stressors or altered nutrient supply. Alpha-arrestins are key decision makers, assuring that this protein reorganization happens correctly and helping proteins get to the right locations inside the cell. This branch of science is young-the term "alpha-arrestin" was coined only in 2008.
"It's actually amazing they went unstudied for such a long time," O'Donnell said, "especially because their jobs are critical to cells-and alpha-arrestins are in almost all cell types.
"If the environment changes, alpha-arrestins can selectively target a specific protein to the cell surface while removing a different protein from that same location. What is the signal sensed by the alpha-arrestin that allows proteins to be selectively transported? "How does the alpha-arrestin recognize the proteins it must move?" O'Donnell asked. "Answering these fundamental biological questions can impact all aspects of cell physiology and can have far reaching clinical implications."
As these important research questions are addressed, high school students in a Taylor Allderdice program; undergraduate and graduate students will gain hands-on research experience; and O'Donnell will incorporate aspects of her research in the curriculum of an undergraduate laboratory course.
"The funds from the NSF grant and the interdisciplinary nature of this research project ensure that trainees at all levels gain exposure to a wide array of scientific approaches," O'Donnell said. "Importantly, students enrolled in my course or those working with me in the lab will get a chance to experience the thrill of scientific discovery and contribute to advancing the boundaries of knowledge in the field of protein trafficking."