Fabian FischerETH Zurich | ETH Zürich · Department of Health Sciences and Technology
Fabian Fischer
Dr. rer. nat.
About
13
Publications
4,428
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348
Citations
Citations since 2017
Introduction
Scientist and Drug Discovery Specialist with 9+ years experience in basic and translational aging research. Focus on identifying drug targets relevant for aging and associated diseases, and on developing screening strategies to identify small molecule compounds to serve as anti-aging drug candidates.
Skills and Expertise
Additional affiliations
January 2013 - present
Position
- Academic advisor
Description
- Design and supervision (i. e. of benchside work and thesis writing) of bachelor and master theses under leading supervision of Prof. Heinz D Osiewacz
January 2012 - present
Position
- Undergraduate course instructor
Description
- Supervision of practical courses on basic molecular biology techniques for undergraduate students
October 2011 - present
Position
- Graduate course instructor
Description
- Supervision of practical courses on advanced molecular biology techniques for graduate students
Education
August 2011 - August 2015
October 2006 - July 2011
Publications
Publications (13)
Physiological aging is a complex process, influenced by a plethora of genetic and environmental factors. While being far from fully understood, a number of common aging hallmarks have been elucidated in recent years. Among these, transcriptomic alterations are hypothesized to represent a crucial early manifestation of aging. Accordingly, several tr...
Interventions and small molecules, which promote formation of reactive oxygen species (ROS), have repeatedly been shown to increase stress resistance and lifespan of different model organisms. These phenotypes occur only in response to low concentrations of ROS, while higher concentrations exert opposing effects. This non-linear or hormetic dose-re...
Maintenance of mitochondria is achieved by several mechanisms, including the regulation of mitochondrial proteostasis. The matrix protease CLPXP, involved in protein quality control, has been implicated in ageing and disease. However, particularly due to the lack of knowledge of CLPXP’s substrate spectrum, only little is known about the pathways an...
Mitochondrial respiratory supercomplexes (mtRSCs) are stoichiometric assemblies of electron transport chain (ETC) complexes in the inner mitochondrial membrane. They are hypothesized to regulate electron flow, the generation of reactive oxygen species (ROS) and to stabilize ETC complexes. Using the fungal ageing model Podospora anserina, we investi...
Mitochondria are organelles of eukaryotic cells with various functions. Best known is their role in energy transduction leading to the formation of ATP. As byproducts of this process, reactive oxygen species (ROS) are formed that can damage different types of molecules leading to mitochondrial dysfunction. Different quality control (QC) mechanisms...
Inhibition of gene expression in Caenorhabditis elegans, a versatile model organism for studying the genetics of development and aging, is achievable by feeding nematodes with bacteria expressing specific double-stranded RNAs. Overexpression of hypoxia inducible factor 1 (hif-1) or heat-shock factor 1 (hsf-1) by conventional transgenesis has previo...
Aging is the single largest risk factor for many debilitating conditions, including heart diseases, stroke, cancer, diabetes, and neurodegenerative disorders. While far from understood in its full complexity, it is scientifically well-established that aging is influenced by genetic and environmental factors, and can be modulated by various interven...
Aging is impacted by interventions across species, often converging on metabolic pathways. Transcription factors regulate longevity yet approaches for their pharmacological modulation to exert geroprotection remain sparse. We show that increased expression of the transcription factor Grainyhead 1 (GRH-1) promotes lifespan and pathogen resistance in...
Mitochondrial maintenance crucially depends on the quality control of proteins by various chaperones, proteases and repair enzymes. While most of the involved components have been studied in some detail, little is known on the biological role of the CLPXP protease complex located in the mitochondrial matrix. Here we show that deletion of PaClpP, en...
Supplementary Figures S1-S5
Questions
Question (1)
My aim is to purify an oligomer-forming protein from isolated fungal mitochondria by TAP. For this purpose I have appended a C-terminal 6x His-TEV-Strep tag II. It should be noted that switching the tag to the N-terminus is, for various reasons, not possible.
With a different monomeric mitochondrial protein (“control protein”) with the exact same tag TAP can be done without a problem. For my protein of interest (POI) I have verified by Western Blot that the full length tag is present and not degraded during lysis/binding steps. Native purification with the 6x His tag works just fine, so supposedly the tag is accessible and not folded away inside the protein. However, there is absolutely no binding of my POI to StrepTactin either in column (StrepTactin Superflow Columns, IBA) or batch (Qiagen StrepTactin Magnetic beads) procedure using the following buffer for lysis/binding: 0,5 % Triton X-100, 300 mM NaCl, 20 mM KPi (pH 7,4) and 1 mM PMSF. The same buffer works for 6x His purification of my POI and also for both 6x His and Strep tag II purification when I do it with the control protein. So I assume there is no general problem with buffer components/composition/handling. In theory I can see no reason why the Strep tag II purification should not work (tag is present, stable and presumably accessible) so I’m really at a loss.
1) Has anyone ever encountered a similar problem, where of two consecutive tags only one was accessible for native purification? I guess it depends on the respective protein, but is it actually feasible that the Strep tag II is sterically inaccessible even though the preceding 6x His tag isn’t?
2) Is it possible for the Strep tag II to somehow become modified and thus unable to bind to StrepTactin?
3) Any suggestions for additives/alterations to the buffer to enhance binding?
4) Would it be advisable to place a Twin-Strep tag directly at the C-terminus seeing as the 6x His directly at the C-terminus is definitely accessible and as this would probably reduce background?
5) Any suggestions for other tags that can be combined with the 6x His tag for TAP from mitochondria?
Projects
Project (1)
Description and analysis of gene expression networks in ageing and disease. Identification and characterization of relevant transcriptional master regulators. Screening for pharmacologically active small-molecule drugs to achieve beneficial reprogramming.
