Detail

Keywords

Allosteric Regulation; Lipids; Membranes; Protein Kinases; Structure-Activity Relationship

Research interests

Membranes are sites of intense signaling activity in eukaryotic cells. Essential processes such as autophagy, cytokinesis, exo- and endo- cytosis, and cytoskeletal remodeling depend on signal propagation at cellular membranes. Dysregulation of signal transduction at these sites is the cause of a number of hereditary and non-hereditary diseases, including Coffin-Lowry syndrome, spinocerebellar ataxia, myotonic dystrophy, and various cancers. Over 500 kinases and 130 phosphatases regulate signal transduction by phosphorylating or dephosphorylating their target proteins. Of the more than 500 kinases, 54 contain known lipid-binding or membrane-interacting domains, and whilst much is known about how these proteins are targeted to cellular membranes, very little is known about how membrane engagement is coupled to signal transduction. Our goal is to understand how lipid second messengers can turn on signaling pathways at the membrane. Many of the lipid responsive human protein kinases belong to the AGC family of kinases, of which the paradigmatic lipid-regulated kinase is protein kinase C (PKC). We would like to understand how lipid-engagement by these protein kinases is coupled to their activation at the molecular level. Ultimately, we hope to elucidate common principles of the molecular mechanisms that govern lipid-mediated signal transduction.

Techniques, methods & infrastructure

Biophysical and structural biology techniques including X-ray crystallography, small angle X-ray scattering (SAXS), and electron microscopy. Protein expression, purification, and characterisation. Biochemical assays, differential scanning fluorimetry, fluorescence microscopy, fluorescence polarisation, and luminescence. Standard molecular biology, including genome editing.

Grants

• Lipid-activated kinases in cell shape and motility (2015)
  Source of Funding: FWF (Austrian Science Fund), Stand-Alone Projects
  Principal Investigator

Selected publications

1. Truebestein, L. et al. (2015) ‘A molecular ruler regulates cytoskeletal remodelling by the Rho kinases’, Nature Communications, 6(1). Available at: http://dx.doi.org/10.1038/ncomms10029.
2. Lucic, I., Truebestein, L. & Leonard, T.A., 2015. Novel features of DAG-activated PKC isozymes reveal a conserved 3-D architecture. Journal of Molecular Biology. Available at: http://dx.doi.org/10.1016/j.jmb.2015.11.001.
3. Leonard, T.A. & Hurley, J.H., 2011. Regulation of protein kinases by lipids. Current Opinion in Structural Biology, 21(6), pp.785-791. Available at: http://dx.doi.org/10.1016/j.sbi.2011.07.006.
4. Leonard, T.A. et al., 2011. Crystal Structure and Allosteric Activation of Protein Kinase C βII. Cell, 144(1), pp.55-66. Available at: http://dx.doi.org/10.1016/j.cell.2010.12.013.
5. Leonard, T.A., Butler, P.J.G., Lowe, J. (2005). Bacterial chromosome segregation: Structure and DNA binding of the Soj dimer ,