DC 5: Cas Koeman
Cas Koeman (Netherlands) obtained his Bachelor’s degree in Plant Sciences from Wageningen University and Research in 2022, followed by a Master’s in Molecular and Cellular Biology at the Ludwig Maximilian University of Munich. He completed research internships at the Gene Center Munich, where he studied the oligomerization and nucleic acid binding of ORF1p in the Stigler lab, and at Helmholtz Munich in the Colomé-Tatché lab, where his Master’s thesis focused on how copy number variation affects the inference of gene regulatory networks from single-cell RNA-sequencing data.
Cas is particularly interested in multidisciplinary approaches at the interface of molecular biology, bioinformatics, and biophysics to understand how small molecular components give rise to complex cellular systems.
In September 2025, he began his PhD at the Institut Necker-Enfants Malades in Paris under the supervision of Mario Pende, as part of the MSCA-DN MENTOR program on mTOR signaling and disease. His research focuses on the functional genomics of S6K1/S6K2-specific substrates regulating cell size.
ORCID
Planned secondments: 3 months at Cell Signalling Technology for PTMScan Ser/Thr Kinase based phosphoproteomics to differentially identify S6K1 and S6K2 targets. 2 months at the University of Tübingen for evalulation of S6K1 versus S6K2 specific inhibitors. 2 months at University of Fribourg for S6K direct kinase assays
Cell Signaling Technology
3 monthsBoston, United States
University of Tübingen
2 monthsTübingen, Germany
University of Fribourg
2 monthsFribourg, Switzerland
My research project
Among the mTORC1 targets, S6 kinases 1 and 2 (S6K1 and S6K2) are exquisitely sensitive to nutrient availability and rapamycin inhibition. Of note, in vivo analysis of mutant mice reveals that S6K1 regulates cell size in a predominant way as compared to S6K2. Mutant animals also mimic a caloric restriction phenotype with decreased adiposity and increased lifespan. S6K1 may be therefore be key to the interconnection between cell size, and regenerative and aging responses. The PhD candidate will perform structure-function studies and phospho-proteomics to reveal:
- selective targets of S6K1 vs. S6K2 mediating cell size control;
- structural changes of key substrates upon phosphorylation;
- suitable residues for the design of covalent S6K1/S6K2 inhibitors.
Molecular biology and genome editing tools will be used to produce mutant kinases and swap relevant domains in S6K1 and S6K2. Phosphoproteomics will broaden the list of S6K1 specific substrates that may be involved in cell size control. Protein modeling will clarify the kinase-substrate as well as inhibitor-kinase interactions in collaboration with the University of Tübingen (Prof. M. Gehringer). The molecular understanding of cell size control by mTOR/S6K1 should open new therapeutic perspectives for mTORopathy in which giant cells are a prominent pathological feature.
PhD enrolment : 
DC 4: Joséphine Cherrière