An overarching goal of synthetic biology is to control and direct the behaviour of living cells. At its most basic level, this can be accomplished by modifying the genetic code of the cell. Although this type of synthetic biology has led to major successes, many other applications remain frustratingly out of reach. One major reason for this is that inserting new genes into an organism is often not enough for the new proteins to assemble together into a functional unit in the modified host.

Our fundamental hypothesis is that geometrical arrangement of proteins and other molecules within cellular signalling systems is both critically important to proper function and synthetically controllable.

Our mission is to combine an arsenal of nanotechnologies and optogenetic methods developed in the three labs, to achieve new levels of synthetic control over the behaviour and function of molecular systems and living cells for therapeutical and pharmacological applications. We will focus on Ras signalling, T cell cancer immunotherapy, and GPCR signalling that represent the backbone of pharmaceutical science and industry.

The principle overarching objectives of the Center for Geometrically Engineered Cellular Systems (GEC) are:

1. To engineer hybrid physically-templated membrane systems to isolate, manipulate, and study the spatial organization and function of key membrane signalling processes.
2. Apply these molecular geometrical engineering tools to modulate cell behaviour, emphasizing T-cells for cancer immunotherapy.
3. Engineer the cellular spatial organization of G protein coupled receptors (GPCRs) for development and screening of drug compounds.

The activities in GEC are thus organized around three work packages (WPs).

• WP1

  Background: The vast majority of cell signalling processes occur on the cell membrane. While the structural and biochemical properties of the individual proteins are reasonably well known, our understanding of how these molecules assemble and work together on the membrane is in its infancy. This gap in understanding has substantial impact on human health and disease because a majority of therapeutic drugs also target processes occurring on the cell membrane.

  Aim: Collectively, we have developed a suite of engineered supported membrane technologies (e.g. (1-7)) as well as optogenetic tools(8, 9) that have been instrumental in a number of significant biological discoveries(4, 7, 10-14). Here, we will integrate these fundamental technologies into a unified engineering platform. We will investigate how the input-output response function relating receptor triggering to the key downstream process of Ras activation is affected by geometric constraint.

• WP2

  Background: The prospect of directing a cancer patient’s own immune system to eradicate their cancer is the fundamental basis of cancer immunotherapy, and one of the most promising breakthroughs in cancer treatment in decades. Despite successes, technical challenges to achieve the full potential of this strategy remain immense(15). Among the difficult aspects of engineering T cells is that natural T cell antigen recognition is a hallmark example of how large-scale spatial movement and assembly of proteins plays a key regulatory role in signalling. Early applications of the spatial mutation technology, developed by the Groves lab and based on patterned supported membranes, played a central role revealing spatial aspects of T cell signalling (11).

  Aim: Here we aim to apply next-generation advanced engineered membrane technologies and optogenetic tools to systematically analyse spatio-mechanical aspects of T cell signalling with the goal of identifying specific points where engineered control over the living cell can be established.

• WP3

  Background: Arguably, the quintessential class of membrane receptors that relays signals across the membrane is G protein coupled receptors (GPCRs). GPCRs comprise the most abundant family of transmembrane proteins in mammalian cells, they control multiple signaling transduction pathways and effect crucial physiological reactions in response to a plethora of endo- and exogenic stimuli.(16) As a result, they are targets to ~40% of all drugs in the market today.

  In a recent publication (Nat. Chem. Biol., 2017, Front Cover Page (17)) the Stamou lab demonstrated that membrane geometry can enable the sorting of GPCRs) in live cells.(17) Remarkably, this sorting was specifically regulated by ligands demonstrating that the biomechanical coupling between membrane geometry and the spatial localization of GPCRs is a sensitive reporter of protein structure/conformation.

  Aim: In WP3, we will engineer a hybrid-cell platform to investigate and if possible manipulate the coupling between membrane geometry, the structural and functional state of GPCRs, and their spatiotemporal organization.

• References

  1. Groves, J.T., N. Ulman, and S.G. Boxer. 1997. Micropatterning fluid lipid bilayers on solid supports. Science. 275: 651–653.
     
     
  2. Baksh, M.M., M. Jaros, and J.T. Groves. 2004. Detection of molecular interactions at membrane surfaces through colloid phase transitions. Nature. 427: 139–141.
     
     
  3. Caculitan, N.G., H. Kai, E.Y. Liu, N. Fay, Y. Yu, T. Lohmüller, G.P. O’Donoghue, and J.T. Groves. 2014. Size-based chromatography of signaling clusters in a living cell membrane. Nano Lett. 14: 2293–2298.
     
     
  4. Hatzakis, N.S., V.K. Bhatia, J. Larsen, K.L. Madsen, P.-Y. Bolinger, A.H. Kunding, J. Castillo, U. Gether, P. Hedegård, and D. Stamou. 2009. How curved membranes recruit amphipathic helices and protein anchoring motifs. Nat Chem Biol. 5: 835–841.
     
     
  5. Mathiasen, S., S.M. Christensen, J.J. Fung, S.G.F. Rasmussen, J.F. Fay, S.K. Jorgensen, S. Veshaguri, D.L. Farrens, M. Kiskowski, B. Kobilka, and D. Stamou. 2014. Nanoscale high-content analysis using compositional heterogeneities of single proteoliposomes. Nat Meth. 11: 931–934.
     
     
  6. Christensen, S.M., P.-Y. Bolinger, N.S. Hatzakis, M.W. Mortensen, and D. Stamou. 2012. Mixing subattolitre volumes in a quantitative and highly parallel manner with soft matter nanofluidics. Nature Nanotech. 7: 51–55.
     
     
  7. Veshaguri, S., S.M. Christensen, G.C. Kemmer, G. Ghale, M.P. Møller, C. Lohr, A.L. Christensen, B.H. Justesen, I.L. Jorgensen, J. Schiller, N.S. Hatzakis, M. Grabe, T.G. Pomorski, and D. Stamou. 2016. Direct observation of proton pumping by a eukaryotic P-type ATPase. Science. 351: 1469–1473.
     
     
  8. Levskaya, A., O.D. Weiner, W.A. Lim, and C.A. Voigt. 2009. Spatiotemporal control of cell signalling using a light-switchable protein interaction. Nature. 461: 997–1001.
     
     
  9. Toettcher, J.E., D. Gong, W.A. Lim, and O.D. Weiner. 2011. Light-based feedback for controlling intracellular signaling dynamics. Nat Meth. 8: 837–839.
     
     
  10. Larsen, J.B., M.B. Jensen, V.K. Bhatia, S.L. Pedersen, T. Bjørnholm, L. Iversen, M. Uline, I. Szleifer, K.J. Jensen, N.S. Hatzakis, and D. Stamou. 2015. Membrane curvature enables N-Ras lipid anchor sorting to liquid-ordered membrane phases. Nat Chem Biol. 11: 192–194.
      
      
  11. Mossman, K.D., G. Campi, J.T. Groves, and M.L. Dustin. 2005. Altered TCR signaling from geometrically repatterned immunological synapses. Science. 310: 1191–1193.
      
      
  12. Salaita, K., P.M. Nair, R.S. Petit, R.M. Neve, D. Das, J.W. Gray, and J.T. Groves. 2010. Restriction of receptor movement alters cellular response: physical force sensing by EphA2. Science. 327: 1380–1385.
      
      
  13. Endres, N.F., R. Das, A.W. Smith, A. Arkhipov, E. Kovacs, Y. Huang, J.G. Pelton, Y. Shan, D.E. Shaw, D.E. Wemmer, J.T. Groves, and J. Kuriyan. 2013. Conformational coupling across the plasma membrane in activation of the EGF receptor. Cell. 152: 543–556.
      
      
  14. Iversen, L., H.-L. Tu, W.-C. Lin, S.M. Christensen, S.M. Abel, J. Iwig, H.-J. Wu, J. Gureasko, C. Rhodes, R.S. Petit, S.D. Hansen, P. Thill, C.-H. Yu, D. Stamou, A.K. Chakraborty, J. Kuriyan, and J.T. Groves. 2014. Ras activation by SOS: allosteric regulation by altered fluctuation dynamics. Science. 345: 50–54.
      
      
  15. Lim, W.A., and C.H. June. 2017. The Principles of Engineering Immune Cells to Treat Cancer. Cell. 168: 724–740.
      
      
  16. Rosenbaum, D.M., S.G.F. Rasmussen, and B.K. Kobilka. 2009. The structure and function of G-protein-coupled receptors. Nature. 459: 356–363.
      
      
  17. Rosholm, K.R., N. Leijnse, A. Mantsiou, V. Tkach, S.L. Pedersen, V.F. Wirth, L.B. Oddershede, K.J. Jensen, K.L. Martinez, N.S. Hatzakis, P.M. Bendix, A. Callan-Jones, and D. Stamou. 2017. Membrane curvature regulates ligand-specific membrane sorting of GPCRs in living cells. Nat Chem Biol. 52: 4114.

For the full lists of publications of the three labs please see:

• Dimitrios Stamou, University of Copenhagen, Department of Chemistry
• Jay Groves, University of California Berkeley, Department of Chemistry
• Orion Weiner, University of California San Francisco, Department of Biochemistry and Biophysics

GEC publications

1. Huang, W.Y.C., S. Alvarez, Y. Kondo, Y.K. Lee, J.K. Chung, H.Y.M. Lam, K.H. Biswas, J. Kuriyan, and J.T. Groves. 2019. A molecular assembly phase transition and kinetic proofreading modulate Ras activation by SOS. Science. 363: 1098–1103.
   
   
2. Tischer, D.K., and O.D. Weiner. 2019. Light-based tuning of ligand half-life supports kinetic proofreading model of T cell signaling. Elife. 8.
   
   
3. Bassereau, P., R. Jin, T. Baumgart, M. Deserno, R. Dimova, V.A. Frolov, P.V. Bashkirov, H. Grubmüller, R. Jahn, H.J. Risselada, L. Johannes, M.M. Kozlov, R. Lipowsky, T.J. Pucadyil, W.F. Zeno, J.C. Stachowiak, D. Stamou, A. Breuer, L. Lauritsen, C. Simon, C. Sykes, G.A. Voth, and T.R. Weikl. 2018. The 2018 biomembrane curvature and remodeling roadmap. J. Phys. D: Appl. Phys. 51: 343001–43.
   
   
4. Walsh, S.M., S. Mathiasen, S.M. Christensen, J.F. Fay, C. King, D. Provasi, E. Borrero, S.G.F. Rasmussen, J.J. Fung, M. Filizola, K. Hristova, B. Kobilka, D.L. Farrens, and D. Stamou. 2018. Single Proteoliposome High-Content Analysis Reveals Differences in the Homo-Oligomerization of GPCRs. Biophys J. 115: 300–312.

Selected relevant publications from the three labs

1. Huang, W.Y.C., S. Alvarez, Y. Kondo, Y.K. Lee, J.K. Chung, H.Y.M. Lam, K.H. Biswas, J. Kuriyan, and J.T. Groves. 2019. A molecular assembly phase transition and kinetic proofreading modulate Ras activation by SOS. Science. 363: 1098–1103.
   
   
2. Rosholm, K.R., N. Leijnse, A. Mantsiou, V. Tkach, S.L. Pedersen, V.F. Wirth, L.B. Oddershede, K.J. Jensen, K.L. Martinez, N.S. Hatzakis, P.M. Bendix, A. Callan-Jones, and D. Stamou. 2017. Membrane curvature regulates ligand-specific membrane sorting of GPCRs in living cells. Nat Chem Biol. 52: 4114.
   
   
3. Larsen, J.B., M.B. Jensen, V.K. Bhatia, S.L. Pedersen, T. Bjørnholm, L. Iversen, M. Uline, I. Szleifer, K.J. Jensen, N.S. Hatzakis, and D. Stamou. 2015. Membrane curvature enables N-Ras lipid anchor sorting to liquid-ordered membrane phases. Nat Chem Biol. 11: 192–194.
   
   
4. Iversen, L., S. Mathiasen, J.B. Larsen, and D. Stamou. 2015. Membrane curvature bends the laws of physics and chemistry. Nat Chem Biol. 11: 822–825.
   
   
5. Tischer, D., and O.D. Weiner. 2014. Illuminating cell signalling with optogenetic tools. Nat Rev Mol Cell Biol. 15: 551–558.
   
   
6. Iversen, L., H.-L. Tu, W.-C. Lin, S.M. Christensen, S.M. Abel, J. Iwig, H.-J. Wu, J. Gureasko, C. Rhodes, R.S. Petit, S.D. Hansen, P. Thill, C.-H. Yu, D. Stamou, A.K. Chakraborty, J. Kuriyan, and J.T. Groves. 2014. Ras activation by SOS: allosteric regulation by altered fluctuation dynamics. Science. 345: 50–54.
   
   
7. Toettcher, J.E., O.D. Weiner, and W.A. Lim. 2013. Using Optogenetics to Interrogate the Dynamic Control of Signal Transmission by the Ras/Erk Module. Cell. 155: 1422–1434.
   
   
8. Toettcher, J.E., D. Gong, W.A. Lim, and O.D. Weiner. 2011. Light-based feedback for controlling intracellular signaling dynamics. Nat Meth. 8: 837–839.
   
   
9. Salaita, K., P.M. Nair, R.S. Petit, R.M. Neve, D. Das, J.W. Gray, and J.T. Groves. 2010. Restriction of receptor movement alters cellular response: physical force sensing by EphA2. Science. 327: 1380–1385.
   
   
10. Levskaya, A., O.D. Weiner, W.A. Lim, and C.A. Voigt. 2009. Spatiotemporal control of cell signalling using a light-switchable protein interaction. Nature. 461: 997–1001.
    
    
11. Hatzakis, N.S., V.K. Bhatia, J. Larsen, K.L. Madsen, P.-Y. Bolinger, A.H. Kunding, J. Castillo, U. Gether, P. Hedegård, and D. Stamou. 2009. How curved membranes recruit amphipathic helices and protein anchoring motifs. Nat Chem Biol. 5: 835–841.
    
    
12. Mossman, K.D., G. Campi, J.T. Groves, and M.L. Dustin. 2005. Altered TCR signaling from geometrically repatterned immunological synapses. Science. 310: 1191–1193.

GEC is a dynamic environment of excellence. We always look for highly motivated and qualified team members. GEC projects are interdisciplinary and are time-shared between the three labs situated in Copenhagen, UC Berkeley and UC San Francisco.

There are currently multiple openings at the MSc, PhD and postdoctoral level.

For more information please send an email to Prof. Dimitrios Stamou with one pdf file containing your motivation letter, CV and publication list. We would prefer if 2-3 letters of reference are included in the pdf, if this is not possible please include the contact details of three referees and ask them to forward their recommendation directly to us.