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Klaus Hahn, PhD

Professor Adjunct
Department of Molecular Medicine
California Campus
Scripps VIVO Scientific Profile
(858) 784-9465

Research Focus

Organization of Signaling in Living Cells

The signaling proteins which control cell behavior act within a complex milieu of rapidly changing cytoplasmic structure. These proteins' subcellular locations and interactions are carefully orchestrated in both time and space to control signaling. In our lab, we are developing new tools to study signaling protein activation within individual, living cells. These tools report the location, level of activation, and kinetics of signaling activity. We synthesize novel fluorescent dyes and site-specifically label proteins to produce sensors of specific conformations or posttranslational modifications. These are loaded into cells, where through quantitative fluorescence microscopy they enable us to study the role of the cytoskeleton in organizing small GTPase signaling. Specifically, we are focusing on polarized cell movement and induction of apoptosis. We have discovered transient activation of Rho family proteins which mediate cell morphological changes, and are beginning to decipher how crosstalk between different extracellular receptors is regulated by the transient formation of multiprotein complexes in vivo.

Professional Experience

2004-2017 Professor Adjunct, Cell and Molecular Biology (CMB), The Scripps Research Institute
2000-2004 Associate Professor, Cell Biology, The Scripps Research Institute
1997-2000 Assistant Professor, Cell Biology, The Scripps Research Institute
1994-1997 Assistant Professor, Neurobiology, The Scripps Research Institute
1987-1992 Postdoctoral Fellow, Carnegie Mellon University

Selected References

All Publications

Hahn, K. and Toutchkine, A. Live cell fluorescent biosensors for activated signaling proteins. Curr. Op Cell Biol. 14:167-172, 2002.

Bark, S. J., Schmid, S., and K. M. Hahn. A highly efficient method for site-specific modification of peptides after chemical synthesis. J. Am. Chem. Soc., 122 (15): 3567-3573, 2000.

Kraynov, V. S., Chamberlain, C. E., Bokoch, G. M., Schwartz, M. A., Slabaugh, S., and K. M. Hahn Localized Rac Activation Dynamics Visualized in Living Cells. Science, 290:333-337, 2000.

Chamberlain, C. E., & Hahn, K. M. (2000). Watching proteins in the wild - fluorescence methods to study protein dynamics in living cells. Traffic, 1: 755-762.