E. Wanker Lab

Confocal microscopy image of a Drosophila brain in which expression of huntingtin with an elongated polyglutamine sequence was turned on for 6 days and turned off for the 18 days that followed. Red: synapses present in all neuronal cells. Green: huntingtin aggregates that form and deposit in the brain.

We have established HD fly models that enable the investigation of huntingtin proteins, their aggregation and seeding specifically in neurons, in vivo. See: Anne Ast et al. “mHTT Seeding Activity: A Marker of Disease Progression and Neurotoxicity in Models of Huntington's Disease”. Molecular Cell. 2018 Sep 6;71(5):675-688.e6. https://doi.org/10.1016/j.molcel.2018.07.032.*

Also, we have developed technologies that enable the quantitative detection of protein-protein interactions (PPIs) in mammalian cells, like our recent LuTHY assay. See: Trepte et al. “LuTHy: A Double-Readout Bioluminescence-Based Two-Hybrid Technology for Quantitative Mapping of Protein-Protein Interactions in Mammalian Cells.” Molecular Systems Biology. 2018 Jul 11;14(7):e8071. https://doi.org/10.15252/msb.20178071.*

In high-throughput screenings using these technologies, we have recently identified various proteins that interact with wild-type and mutant huntingtin in cell models. Among them, ubiquitin protein ligases (UBLs) and deubiquitinating enzymes (DUBs) are of particular interest to us, because they are known to regulate the degradation of other proteins in mammalian cells.
We are now looking for a PhD candidate to join our team to help elucidate the molecular mechanisms that control wild-type and mutant huntingtin protein levels. Specifically, the project will investigate the influence of E3 ligases and DUBs on the abundance of
wild-type and mutant huntingtin in cell models and in HD transgenic flies.

Using the CRISPR/Cas9 technology on mammalian cells, we will generate cell lines that endogenously express huntingtin fusions, which are tagged with nanoluciferase or fluorescent proteins such mCitrine or mNeonGreen. These cell lines will be used to determine the huntingtin dynamics but also to validate huntingtin-interacting UBL and DUB proteins.

Moreover, through knockdown and overexpression of selected ubiquitin and DUB proteins, e.g., the E3 ligase UBR5, we will assess whether the degradation of mutant huntingtin can be promoted. To this end, we want to determine whether the ubiquitin proteasome system (UPS) or autophagy are predominantly responsible for mutant huntingtin degradation in cells. Furthermore, HD transgenic flies will be used to investigate whether huntingtin degradation in non-dividing post-mitotic neurons is different from fast-dividing non-neuronal cells. Altogether, this work will bring significant contributions to finding a new huntingtin lowering strategy, which is one of the most promising current approaches in the search of treatments for Huntington’s disease.

Become a member of a highly motivated, fun and collaborative team full of ideas. As part of our team you will learn, use and develop a set of sophisticated biochemical, biophysical, cellular, genetic, proteomic, imaging and fly techniques to make a significant contribution towards the elucidation and future therapy of Huntington’s disease.

Our group has been active in protein misfolding disorders and interactomics for many years and has made several pioneering discoveries: The identification of protein aggregation in Huntington’s disease (Scherzinger et al. Cell, 1997), the generation of the first genome-wide protein-protein interaction network (Stelzl et al. Cell, 2005) or the effect of small molecules on misfolded protein species relevant to disease (Ehrnhoefer et al. Nature Structural and Molecular Biology, 2006; Bieschke et al.
Nature Chemical Biology, 2011).

* For a more general review of the significance of Ast et al., see:
https://www.mdc-berlin.de/news/press/predicting-onset-and-course-huntingtons-disease
* For commentary on Trepte et al., see:
https://www.embopress.org/doi/full/10.15252/msb.20188485
https://www.mdc-berlin.de/news/news/two-experiments-one-fell-swoop

Looking forward to meeting enthusiastic candidates!

About our research:

Millions of people worldwide suffer from neurodegenerative disorders, like Alzheimer’s, Parkinson’s or Huntington’s disease. Most of these illnesses break out later in life. Correlated to the current demographic shift towards aging societies in many countries, the number of people affected with neurodegenerative diseases is growing.

Still, we do not understand exactly how neurodegenerative diseases develop. One of the characteristic features many neurodegenerative diseases share is the deposition of abnormally folded proteins in patient brains.

My group's research focusses on ‘Neuroproteomics’, the protein-based investigation of neurodegenerative diseases. We aim to elucidate the molecular principles by which proteins, sometimes abnormally folded, alone or in interaction, lead to cellular toxicity and neuronal dysfunction, causing neurodegeneration.

We pursue two main lines of investigation: Hypothesis-driven molecular studies of protein misfolding, aggregation and spreading, on the one hand, unbiased protein-protein interaction or ‘interactomics’ studies on the other. Click "Research" above to read about our current projects and fields of interest.

Jan 26, 2021: PhD recruitment round for spring 2021: We are participating. Please check out our lab's project:

How do proteins that interact with mutated huntingtin affect its abundance? A study of Huntington’s disease in cell models and neurons of Drosophila melanogaster

Looking forward to meeting enthusiastic candidates!

My group's research focusses on ‘Neuroproteomics’, the protein-based investigation of neurodegenerative diseases. In detailed, hypothesis-driven studies we address mechanisms of protein misfolding and aggregation, with the aim of understanding the molecular mechanisms of neurodegeneration in Huntington’s, Alzheimer’s and further diseases causally related to the misfolding of proteins. In particular, we aim to elucidate the molecular principles by which abnormally folded proteins, their complexes and aggregates cause cellular toxicity and neuronal dysfunction. In our efforts to promote translation of basic research into benefits for patients, we identify and characterize modulators of protein misfolding cascades in disease (Ehrnhoefer et al., Nat Struct Mol Biol, 2008; Bieschke et al., Nat Chem Biol, 2011). We have previously demonstrated that expanded polyglutamine (polyQ) sequences trigger misfolding and aggregation of N-terminal huntingtin fragments in vitro and in vivo (Scherzinger et al., Cell, 1997; Davis et al., Cell, 1997). More recently, we have started new lines of translational research establishing methods to detect disease-relevant misfolded protein species in biosamples from models and patients. These investigations are directed at the development of predictive disease markers which are a prerequisite for the clinical investigation of new disease-modifying therapies targeting neurodegeneration before symptoms of irreversible neuronal damage arise. In collaboration with Alessandro Prigione, a Delbrück Fellow I have been mentoring since 2013, we have established stem cell research strategies for the rare neurological Leigh syndrome and Huntington’s disease (Lorenz et al. Cell Stem Cell, 2017).

Our second field of activity is systems biology, in particular using interactomics approaches, which are also mainly applied to neurodegenerative disease processes. Previously, we developed an automated yeast two-hybrid (Y2H) system, which we used to generate a focused protein-protein interaction network for the huntingtin protein relevant to Huntington's disease (Goehler et al., Mol. Cell, 2004), as well as a large interaction map of the human proteome (Stelzl et al., Cell, 2005). Recently, we identified highly relevant interactions between the triple A ATPase VCP/p97 and an adaptor protein that effects a fundamental structural change in VCP from a homohexamer to a heterooligomer with far-reaching functional implications (Arumughan et al. 2016). We are constantly developing more powerful methods for the identification and validation of protein-protein interactions, most recently LuTHy, a double readout luminescence-based technology for interactome mapping in mammalian cells (Trepte et al., Mol Syst Biol, 2018).