Franz Hagn
Technical University of Munich, Institute of Structural Biology, Germany
Structural basis of apoptosis induction by mitochondrial Bcl2 proteins and their complexes
Bcl2 proteins govern the intrinsic pathway of apoptosis at the outer mitochondrial membrane (OMM). The concentration ratio of the individual Bcl2 family members determines whether large pores are formed to release pro-apoptotic inducers, such as cytochrome C. To enable or inhibit pore formation, Bcl2 proteins must be located at the OMM surface, which induces large conformational changes in pore-forming Bcl2 proteins upon activation. We have developed biochemical tools for studying membrane proteins in a native lipid environment by structural methods and in particular NMR, which is a crucial factor for this conformationally labile protein class. This talk will cover recent developments in my lab on membrane protein structural biology using so-called lipid nanodiscs – a self-assembling native lipid membrane mimetic – as well as protein ligation tools that can be used for segmental isotope labeling for NMR. Furthermore, I will share (un)-published structural insights on Bcl2 protein structure determination, activation, and complex formation at the membrane surface. In addition, I will discuss unpublished work on mechanistic details of apoptosis induction by the voltage-dependent anion channel subtype 1 (VDAC-1).
Selected publications
- Daniilidis M, Brandl, MJ and Hagn F, The advanced properties of circularized MSP nanodiscs facilitate high-resolution NMR studies of membrane proteins, J Mol Biol 434 (2022), 167861
- Günsel U and Hagn F, Lipid nanodiscs for high-resolution NMR studies of membrane proteins, Chem Rev 122 (2022), 9395–9421
- Sperl LE, Rührnößl F, Schiller A, Haslbeck M and Hagn F, High-resolution analysis of the conformational transition of pro-apoptotic Bak at the lipid membrane, EMBO J 40 (2021), e107159
- Reif M, Fischer M, Fredriksson K, Hagn F and Zacharias M, The N-terminal segment of the voltage-dependent anion channel: A possible membrane-bound intermediate in pore unbinding. J Mol Biol 431 (2019), 223-243
- Miehling J, Goricanec D, and Hagn F, A split‐intein‐based method for the efficient production of circularized nanodiscs for structural studies of membrane proteins. ChemBioChem 19 (2018), 1927-1933
- Raltchev K, Pipercevic J, and Hagn F, Production and structural analysis of membrane-anchored proteins in phospholipid nanodiscs. Chem - Eur J 24 (21) (2018), 5493-5499
- Hagn F, Nasr ML and Wagner G, Assembly of phospholipid nanodiscs of controlled size for structural studies of membrane proteins by NMR. Nat Protoc 13 (2018), 79–98
- Hagn F, Etzkorn M, Raschle T, and Wagner G, Optimized Phospholipid Bilayer Nanodiscs For High-Resolution Structure Determination of Membrane Proteins. J Am Chem Soc 135 (2013) 1919-1925