Membrane Dynamics

Ana García-Sáez

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  • PhD in Biochemistry and Molecular Biology, University of Valencia, 2005
  • Postdoctoral training in Biophysics, BIOTEC, TU Dresden, 2005-2009
  • Group leader, MPI for Intelligent Systems and German Cancer Research Center, BioQuant, Heidelberg 
  • Professor of Biochemistry at the IFIB since 2013

Research Interest

Our research is focused on the study of dynamic membrane processes from a quantitative point of view. We have a special interest in mitochondrial dynamics, its alterations during apoptosis and the mechanism of action of the Bcl-2 proteins. To address these problems, we make use of our expertise in membrane biophysics, advanced microscopy and single molecule techniques.

We apply superresolution microscopy, fluorescence correlation spectroscopy, atomic force microscopy and single molecule imaging to in vitro reconstituted systems in order to characterize the complex interaction networks between the members of the Bcl-2 proteins. Moreover, we are interested in understanding the molecular mechanisms of membrane permeabilization, fission and fusion and how they are related to apoptosis regulation. Our desire is to use the quantitative insight provided by advanced microscopy and single molecule techniques to build a mathematical model for the mitochondrial pathway of apoptosis.

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Quantification of interactions between Bcl-2 proteins by fluorescence correlation spectroscopy (FCS). A) Signaling network of Bcl-2 family. B) Principle of two-focus scanning FCS to quantify protein interactions within membranes. C) Quantification of interactions between tBid and Bcl-xL in membranes by FCS.

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Model membrane systems. A) Supported lipid bilayer imaged with atomic force microscopy. B) Giant unilamellar vesicle with lipid domains imaged with confocal microscopy. C) Cellular bleb imaged with confocal microscopy. D) Live cell imaging with confocal microscopy.

Available PhD Projects

Single molecule analysis of apoptosis signaling: how life and death decisions are orchestrated.

Selected Reading

1) Salvador-Gallego R, Mund M, Cosentino K, Schneider J, Unsay J, Schraermeyer U, Engelhardt J, Ries J, García-Sáez AJ. Bax assembly into rings and arcs in apoptotic mitochondria is linked to membrane pores. EMBO J. 2016 Feb 15;35(4):389-401.

2) Subburaj Y, Cosentino K, Axmann M, Pedrueza-Villalmanzo E, Hermann E, Bleicken S, Spatz J, García-Sáez AJ. Bax monomers form dimer units in the membrane that further self-assemble into multiple oligomeric species. Nat Commun. 2015 Aug 14;6:8042.

3) Bleicken S, Jeschke G, Stegmueller C, Salvador-Gallego R, García-Sáez AJ, Bordignon E. Structural model of active Bax at the membrane. Mol Cell. 2014 Nov 20;56(4):496-505.