Principal Investigator:

Arminja Kettenbach
Associate Professor of Biochemistry and Cell Biology
Member Norris Cotton Cancer Center

Education: Diplom (equivalent M. Sc.) Eberhard-Karls University Tübingen, Germany
Dr. rer. nat (summa cum laude, equivalent Ph.D.) Eberhard-Karls University, Tübingen, Germany and Harvard Medical School, Boston

Bio: Arminja received her Diploma and Ph.D from Eberhard-Karls University, Tübingen, Germany. She conducted her graduate student work under the supervision of Dr. Frank McKeon at Harvard Medical School in collaboration with Eberhard-Karls University. Her graduate work was focused on mechanisms of cell differentiation and division. She then pursued a postdoctoral fellowship in the field of mass spectrometry-based proteomics in the laboratory of Dr. Scott Gerber at the Geisel School of Medicine at Dartmouth, where she conducted large-scale quantitative chemical phosphoproteomics experiments using small molecule inhibitors to identify substrates of the mitotic kinases Polo-like kinase 1, Aurora kinase A, and Aurora kinase B. Furthermore, she developed a more efficient workflow for phosphopeptide enrichment and a new approach for the identification of protein kinase motifs using mass spectrometry.

As an independent investigator, Arminja is interested in determining how protein dephosphorylation contributes to faithful chromosome segregation, mitotic progression, and maintenance of genomic stability. Using biochemical and cell biological approaches in combination with microscopy and quantitative proteomics, the lab investigates the role of protein phosphatases in mitotic progression, their regulation, substrate targeting mechanisms, and kinase counter-action.

Dr. Arminja Kettenbach’s CV

Postdoctoral fellows:

Isha Nasa
Education: Ph.D. University of Calgary

Isha completed her Ph.D. in Protein Biochemistry from University of Calgary in 2016. Her research interests focus on understanding the regulation of phospho-protein phosphatases (PPP) during cell cycle. Isha is using mass spectrometry-based proteomic and phospho-proteomic approaches to identify and characterize substrates of protein phosphatases in different signaling contexts. Using these methods, she has recently mapped the differential phosphorylation sites on endogenous phosphatase catalytic and regulatory proteins in asynchronous and mitotic cells revealing a phosphorylation-based inhibition mechanism for PP2A activity in mitosis.

Graduate Students:

Natasha Mariano
Education: B.S. Bridgewater State University

Natasha graduated from Bridgewater State University with a BS in Chemistry in 2014. After graduation, she worked as a lab manager at Stanford University investigating stem cell self-renewal mechanisms. She joined the lab as a PhD candidate in the MCB Program in 2018 and her research now focuses on characterizing the role of phosphoprotein phosphatases in mammalian cells, particularly in the context of the DNA damage response system. She is also investigating novel therapeutic targets for Triple-negative Breast Cancer subtypes using mass spectrometry-based, proteomic approaches.

Hieu T. Nguyen
Education: University of New Hampshire

Hieu graduated from University of New Hampshire with a B.S. in Biochemistry, Molecular and Cellular Biology in 2018. He joined the MCB Program at Dartmouth in the Fall of 2018 and officially joined the Kettenbach Lab the following Summer. In the lab, his research interests focus on identifying substrates, charactering substrate binding and dephosphorylation mechanisms for PP2A as dictated by its regulatory subunits, and PP1.

Kali A. Smolen
Education: Grand Valley State University

Kali is a 2017 graduate in Cell and Molecular Biology from Grand Valley State University in her home state of Michigan. She originally rotated in the Kettenbach Lab as an MD-PhD Undergraduate Summer Fellow in 2016 and officially joined the lab in summer 2019 as part of the MD-PhD program at the Geisel School of Medicine at Dartmouth. Her work focuses on characterizing enzyme-substrate relationships of PP2A- a key phosphatase that acts as a tumor suppressor and regulator of many cellular processes and signaling cascades.

Brennan C. McEwan
Education: Utah State University

Brennan is a 2019 graduate in Molecular and Cellular Biology from Utah State University. His research is focused on the targeting specificity and substrates of PP2A-B55, a key regulator of mitotic exit. He is also involved in projects involving PPP6C and investigating purported PP2A-activating compounds.

Nod (Nawat) Bunnag
Education: Yale-NUS College

Nod graduated with a B.Sc. degree in Life Sciences from Yale-NUS College in 2019. His research is focused on understanding the role of PP2A-B56 in regulating Wnt signaling. Using a combination of proteomics-based approaches and Drosophila genetics, he is also interested in unraveling novel regulatory mechanisms and post-translational modifications in Wnt signaling conserved from flies to humans.

Galini Poimenidou

Education: Lawrence University

Galini graduated from Lawrence University with a B.A. in Biochemistry and Economics in 2020. She joined the MCB Program at Dartmouth in the Fall of 2020 and officially joined the Kettenbach Lab the following Summer. In the lab, Galini’s research focuses on elucidating the mechanisms of PP1 holoenzyme assembly, with an emphasis on isoform preference, through mass spectrometry based proteomics.


Karl Biggs

Education: UCLA

Karl graduated from UCLA with a B.S. in neuroscience in 2018. His research is focused on cellular mechanisms underlying the neuroimmune response in neurodegenerative disease like Parkinson’s and Alzheimer’s disease. He is specifically interested in extracellular vesicles packaged and released from microglia that are reactive to protein aggregates. He is also investigating PP2A regulation of tau hyperphosphorylation in diseases such as Alzheimer’s disease.


Rachel Riley

Education: Moravian University

Rachel graduated from Moravian University in 2022 with her Bachelor’s of Science in Biochemistry. She joined the MCB program at Dartmouth in the fall of 2022, and she joined the Kettenbach lab in the spring of 2023. Rachel’s work focuses on the protein phosphatase PP6, and she is investigating protein interactions, holoenzyme structure, and interconnectivity with key signaling pathways including the MAPK cascade.



Amber D. Austin

Education: Hampton University

Amber Austin is a third-year Biochemistry major and Public Health minor at Hampton University. Amber joined the Kettenbach Lab during the summer of 2023, as an undergraduate researcher. Her project focused on identifying a candidate short linear motif for PP2A. She will return to the lab next summer to continue her work.



Mark Adamo
Education: B.S. Vassar College

Mark is a 2013 graduate in Computer Science and Psychology from Vassar College. Mark keeps our proteomics pipeline running, develops software, and helps everybody in the lab with data analysis.

Research Associates:


Dr. Brooke Brauer
Current: AstraZeneca
Education: B.A. Wittenberg University, MCB PhD Program Geisel School of Medicine at Dartmouth

Brooke identified substrates and phosphosites for the phosphoprotein phosphatase PP2B, as well as characterized breast cancer subtypes based off their PPPome.

Lauren Cressey
Education: B.S. Wheaton College




Dr. Scott Lyons
Current: Duke University 
Education: B.S. Sunny – Bingham, MCB PhD Program Geisel School of Medicine at Dartmouth

Scott developed a new chemical proteomics approach to profile endogenous phosphoprotein phosphatases (PPP) in cells and tissues. Using this approach, he identified carboxyl-terminal methylation of PPP catalytic subunits and investigated the function of this modification. 

Dr. David (Youdinghuan) Chen
Education: QBS PhD Program Geisel School of Medicine at Dartmouth

David’s research focused on investigating triple-negative breast cancer tumors. Using proteomics and genomics methods, he generated a classifier to identify BRCA-like characteristics.




Jack Sears
Current: University of North Carolina Chapel Hill
Education: B.S. Colby College

Jack graduated in 2017 from Colby College. He was in charge of organizing the lab and keeping everybody and everything in check, which by itself is a full-time job. Jack’s research focused on investigating Protein Phosphatase 6 in melanoma.



Scott Rusin - Graduate Student

Dr. Scott Rusin
Current: Kymera Therapeutics
Education: B.S. Arizona State University, MCB PhD Program Geisel School of Medicine at Dartmouth

Scott is a 2008 graduate of Arizona State University in Molecular Biosciences and Biotechnology. After graduation, Scott worked as a Research Technician at Albany Medical College and later as a Research Associate at the Broad Institute of Harvard and MIT, Boston, where he participated in Project Achilles, a systematic interrogation of the human genome to identify lineage-specific lethal genes in cancer cells. Scott’s research focused on developing novel proteomics approaches to investigate phosphoprotein phosphatase function and substrate recognition mechanisms.

Nicole Jenkins
Current: College of Osteopathic Medicine, University of New England
Education: B.S. Wheaton College

Nikki’s research focused on investigating phosphorylation signaling in triple negative breast cancer tumors by quantitative proteomics and molecular mechanism of phosphoprotein phosphatase signaling.

Kate Schlosser - Research Associate

Kate Schlosser
Current: Research Associate Berg LLC
Education: B.S. University of Vermont

Kate graduated in 2012 from the University of Vermont. Since her undergraduate research with Dr. Bryan Ballif at UVM, Kate has a strong interest in mass spectrometry-based proteomics. At Dartmouth, Kate was developing novel approaches for in vivo tagging and purification. She used quantitative proteomics to determine the molecular composition of these unique macromolecular complexes.

Jason Rodriguez
Current: Postbaccalaureate Research Education Program (PREP) John Hopkins University
Education: B.S. California State University, Monterey Bay

Jason was an undergraduate at California State University, Monterey Bay who joined the lab in summer 2014 as part of the MD-PhD Undergrad Summer Fellowship.




Brittany Toffey
Current: Rutgers New Jersey Medical School
Education: B.A. Dartmouth College

Brittany was an undergraduate at Dartmouth College who is studying Biology.  She joined the lab in Fall 2014 and was working with Adam on purifying potentially novel cdk substrates .






Adam Petrone - graduate student

Adam Petrone
Current: Research Associate Juno Therapeutics Inc.
Education: B.S. Susquehanna University, M.S. Dartmouth College

Adam graduated in 2012 from Susquehanna University with a degree in Biology. Adam’s work focused on identifying Cdk1 substrates and their function in the regulation of mitotic progression using quantitative phosphoproteomics approaches.