Project acronym ERAD_SELMA
Project Mechanisms of protein translocation in ER-associated protein degradation and the related protein import into the apicoplast of Plasmodium falciparum
Researcher (PI) Alexander Stein
Host Institution (HI) MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV
Call Details Starting Grant (StG), LS1, ERC-2015-STG
Summary The removal of misfolded proteins is an essential process in all cells. Failure to dispose of such proteins often results in disease. A particularly intriguing process serves to discard misfolded proteins from the endoplasmic reticulum (ER). The ER does not itself degrade proteins, so machinery has evolved that moves misfolded proteins into the cytosol where they can be degraded by the proteasome. This retro-translocation process is called ERAD (for ER-associated protein degradation). By comparison with other membrane translocation processes, the mechanism of ERAD is poorly understood. How are misfolded proteins distinguished from folding intermediates? How are proteins moved across the membrane? How is the energy for membrane translocation provided? To answer these fundamental questions I will use a combination of in vitro reconstitution experiments with purified proteins from S. cerevisiae and experiments in intact yeast cells. It appears that some ERAD components have been adapted to function in protein translocation in a very different setting. Many parasites like the malaria causing P. falciparum contain a plastid-like organelle, called the apicoplast. It is the site of several metabolic pathways essential for the parasite’s survival, and thus an important drug target. Like other organelles of endosymbiotic origin, the apicoplast lost most of its genetic information and has to import proteins. This is a particularly challenging endeavour because four membranes surround the apicoplast. It is thought that symbiont specific ERAD-like machinery (SELMA) mediates proteins translocation across the second-outermost membrane. However, not much is known about SELMA. What is its molecular composition? Which aspects of SELMA are conserved in comparison to the classical ERAD machinery? I will address these important questions using a completely novel combination of biochemical and genetic approaches.
Summary
The removal of misfolded proteins is an essential process in all cells. Failure to dispose of such proteins often results in disease. A particularly intriguing process serves to discard misfolded proteins from the endoplasmic reticulum (ER). The ER does not itself degrade proteins, so machinery has evolved that moves misfolded proteins into the cytosol where they can be degraded by the proteasome. This retro-translocation process is called ERAD (for ER-associated protein degradation). By comparison with other membrane translocation processes, the mechanism of ERAD is poorly understood. How are misfolded proteins distinguished from folding intermediates? How are proteins moved across the membrane? How is the energy for membrane translocation provided? To answer these fundamental questions I will use a combination of in vitro reconstitution experiments with purified proteins from S. cerevisiae and experiments in intact yeast cells. It appears that some ERAD components have been adapted to function in protein translocation in a very different setting. Many parasites like the malaria causing P. falciparum contain a plastid-like organelle, called the apicoplast. It is the site of several metabolic pathways essential for the parasite’s survival, and thus an important drug target. Like other organelles of endosymbiotic origin, the apicoplast lost most of its genetic information and has to import proteins. This is a particularly challenging endeavour because four membranes surround the apicoplast. It is thought that symbiont specific ERAD-like machinery (SELMA) mediates proteins translocation across the second-outermost membrane. However, not much is known about SELMA. What is its molecular composition? Which aspects of SELMA are conserved in comparison to the classical ERAD machinery? I will address these important questions using a completely novel combination of biochemical and genetic approaches.
Max ERC Funding
1 500 000 €
Duration
Start date: 2016-03-01, End date: 2021-02-28
Project acronym MolMap
Project From Tissues to Single Molecules: High Content in Situ Super-Resolution imaging with DNA-PAINT
Researcher (PI) Ralf Jungmann
Host Institution (HI) LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN
Call Details Starting Grant (StG), LS1, ERC-2015-STG
Summary Fluorescence microscopy is a powerful tool for exploring biomolecules in cells and tissues, especially with the advent of super-resolution techniques. To better understand key processes such as cell differentiation and disease progression, it is crucial to investigate the abundance, localization and mutual interactions of crucial cellular components such as nucleic acids and proteins. Unraveling their complex interplay in whole signaling networks is necessary to investigate cellular responses to stimuli. However, currently available characterization techniques are either limited by low multiplexing capability (e.g. fluorescence microscopy) or lack localization information (e.g. mass spectrometry). Despite the immense biological and clinical relevance of understanding network-wide changes, the lack of a technological platform to image, identify and quantify a multitude of key protein networks at high spatial resolution in tissues impedes our understanding of the molecular basis of health and disease.
I aim to solve this pressing issue and revolutionize fluorescence microscopy using tools from DNA Nanotechnology with transformative potential to positively answer the question: Can we localize and identify each protein or nucleic acid molecule in a complex tissue microenvironment?
The approach is based on my recently developed DNA- and Exchange-PAINT techniques. To push the envelope of what’s technically possible I will first build a lattice light-sheet microscope for deep tissue high throughput DNA-PAINT imaging. Second, I will develop novel nanobody- and aptamer-based labeling approaches in combination with molecular barcoding and automated multiplexed image acquisition and processing.
With these disruptive and transformative tools, I will investigate whole signaling cascades at once in single cells and whole tissues, thus enabling quantitative imaging transcriptomics and proteomics with highest spatial resolution.
Summary
Fluorescence microscopy is a powerful tool for exploring biomolecules in cells and tissues, especially with the advent of super-resolution techniques. To better understand key processes such as cell differentiation and disease progression, it is crucial to investigate the abundance, localization and mutual interactions of crucial cellular components such as nucleic acids and proteins. Unraveling their complex interplay in whole signaling networks is necessary to investigate cellular responses to stimuli. However, currently available characterization techniques are either limited by low multiplexing capability (e.g. fluorescence microscopy) or lack localization information (e.g. mass spectrometry). Despite the immense biological and clinical relevance of understanding network-wide changes, the lack of a technological platform to image, identify and quantify a multitude of key protein networks at high spatial resolution in tissues impedes our understanding of the molecular basis of health and disease.
I aim to solve this pressing issue and revolutionize fluorescence microscopy using tools from DNA Nanotechnology with transformative potential to positively answer the question: Can we localize and identify each protein or nucleic acid molecule in a complex tissue microenvironment?
The approach is based on my recently developed DNA- and Exchange-PAINT techniques. To push the envelope of what’s technically possible I will first build a lattice light-sheet microscope for deep tissue high throughput DNA-PAINT imaging. Second, I will develop novel nanobody- and aptamer-based labeling approaches in combination with molecular barcoding and automated multiplexed image acquisition and processing.
With these disruptive and transformative tools, I will investigate whole signaling cascades at once in single cells and whole tissues, thus enabling quantitative imaging transcriptomics and proteomics with highest spatial resolution.
Max ERC Funding
1 695 000 €
Duration
Start date: 2016-04-01, End date: 2021-03-31
