Project acronym 20SComplexity
Project An integrative approach to uncover the multilevel regulation of 20S proteasome degradation
Researcher (PI) Michal Sharon
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), LS1, ERC-2014-STG
Summary For many years, the ubiquitin-26S proteasome degradation pathway was considered the primary route for proteasomal degradation. However, it is now becoming clear that proteins can also be targeted for degradation by a ubiquitin-independent mechanism mediated by the core 20S proteasome itself. Although initially believed to be limited to rare exceptions, degradation by the 20S proteasome is now understood to have a wide range of substrates, many of which are key regulatory proteins. Despite its importance, little is known about the mechanisms that control 20S proteasomal degradation, unlike the extensive knowledge acquired over the years concerning degradation by the 26S proteasome. Our overall aim is to reveal the multiple regulatory levels that coordinate the 20S proteasome degradation route.
To achieve this goal we will carry out a comprehensive research program characterizing three distinct levels of 20S proteasome regulation:
Intra-molecular regulation- Revealing the intrinsic molecular switch that activates the latent 20S proteasome.
Inter-molecular regulation- Identifying novel proteins that bind the 20S proteasome to regulate its activity and characterizing their mechanism of function.
Cellular regulatory networks- Unraveling the cellular cues and multiple pathways that influence 20S proteasome activity using a novel systematic and unbiased screening approach.
Our experimental strategy involves the combination of biochemical approaches with native mass spectrometry, cross-linking and fluorescence measurements, complemented by cell biology analyses and high-throughput screening. Such a multidisciplinary approach, integrating in vitro and in vivo findings, will likely provide the much needed knowledge on the 20S proteasome degradation route. When completed, we anticipate that this work will be part of a new paradigm – no longer perceiving the 20S proteasome mediated degradation as a simple and passive event but rather a tightly regulated and coordinated process.
Summary
For many years, the ubiquitin-26S proteasome degradation pathway was considered the primary route for proteasomal degradation. However, it is now becoming clear that proteins can also be targeted for degradation by a ubiquitin-independent mechanism mediated by the core 20S proteasome itself. Although initially believed to be limited to rare exceptions, degradation by the 20S proteasome is now understood to have a wide range of substrates, many of which are key regulatory proteins. Despite its importance, little is known about the mechanisms that control 20S proteasomal degradation, unlike the extensive knowledge acquired over the years concerning degradation by the 26S proteasome. Our overall aim is to reveal the multiple regulatory levels that coordinate the 20S proteasome degradation route.
To achieve this goal we will carry out a comprehensive research program characterizing three distinct levels of 20S proteasome regulation:
Intra-molecular regulation- Revealing the intrinsic molecular switch that activates the latent 20S proteasome.
Inter-molecular regulation- Identifying novel proteins that bind the 20S proteasome to regulate its activity and characterizing their mechanism of function.
Cellular regulatory networks- Unraveling the cellular cues and multiple pathways that influence 20S proteasome activity using a novel systematic and unbiased screening approach.
Our experimental strategy involves the combination of biochemical approaches with native mass spectrometry, cross-linking and fluorescence measurements, complemented by cell biology analyses and high-throughput screening. Such a multidisciplinary approach, integrating in vitro and in vivo findings, will likely provide the much needed knowledge on the 20S proteasome degradation route. When completed, we anticipate that this work will be part of a new paradigm – no longer perceiving the 20S proteasome mediated degradation as a simple and passive event but rather a tightly regulated and coordinated process.
Max ERC Funding
1 500 000 €
Duration
Start date: 2015-04-01, End date: 2020-03-31
Project acronym ABATSYNAPSE
Project Evolution of Alzheimer’s Disease: From dynamics of single synapses to memory loss
Researcher (PI) Inna Slutsky
Host Institution (HI) TEL AVIV UNIVERSITY
Call Details Starting Grant (StG), LS5, ERC-2011-StG_20101109
Summary A persistent challenge in unravelling mechanisms that regulate memory function is how to bridge the gap between inter-molecular dynamics of single proteins, activity of individual synapses and emerging properties of neuronal circuits. The prototype condition of disintegrating neuronal circuits is Alzheimer’s Disease (AD). Since the early time of Alois Alzheimer at the turn of the 20th century, scientists have been searching for a molecular entity that is in the roots of the cognitive deficits. Although diverse lines of evidence suggest that the amyloid-beta peptide (Abeta) plays a central role in synaptic dysfunctions of AD, several key questions remain unresolved. First, endogenous Abeta peptides are secreted by neurons throughout life, but their physiological functions are largely unknown. Second, experience-dependent physiological mechanisms that initiate the changes in Abeta composition in sporadic, the most frequent form of AD, are unidentified. And finally, molecular mechanisms that trigger Abeta-induced synaptic failure and memory decline remain elusive.
To target these questions, I propose to develop an integrative approach to correlate structure and function at the level of single synapses in hippocampal circuits. State-of-the-art techniques will enable the simultaneous real-time visualization of inter-molecular dynamics within signalling complexes and functional synaptic modifications. Utilizing FRET spectroscopy, high-resolution optical imaging, electrophysiology, molecular biology and biochemistry we will determine the casual relationship between ongoing neuronal activity, temporo-spatial dynamics and molecular composition of Abeta, structural rearrangements within the Abeta signalling complexes and plasticity of single synapses and whole networks. The proposed research will elucidate fundamental principles of neuronal circuits function and identify critical steps that initiate primary synaptic dysfunctions at the very early stages of sporadic AD.
Summary
A persistent challenge in unravelling mechanisms that regulate memory function is how to bridge the gap between inter-molecular dynamics of single proteins, activity of individual synapses and emerging properties of neuronal circuits. The prototype condition of disintegrating neuronal circuits is Alzheimer’s Disease (AD). Since the early time of Alois Alzheimer at the turn of the 20th century, scientists have been searching for a molecular entity that is in the roots of the cognitive deficits. Although diverse lines of evidence suggest that the amyloid-beta peptide (Abeta) plays a central role in synaptic dysfunctions of AD, several key questions remain unresolved. First, endogenous Abeta peptides are secreted by neurons throughout life, but their physiological functions are largely unknown. Second, experience-dependent physiological mechanisms that initiate the changes in Abeta composition in sporadic, the most frequent form of AD, are unidentified. And finally, molecular mechanisms that trigger Abeta-induced synaptic failure and memory decline remain elusive.
To target these questions, I propose to develop an integrative approach to correlate structure and function at the level of single synapses in hippocampal circuits. State-of-the-art techniques will enable the simultaneous real-time visualization of inter-molecular dynamics within signalling complexes and functional synaptic modifications. Utilizing FRET spectroscopy, high-resolution optical imaging, electrophysiology, molecular biology and biochemistry we will determine the casual relationship between ongoing neuronal activity, temporo-spatial dynamics and molecular composition of Abeta, structural rearrangements within the Abeta signalling complexes and plasticity of single synapses and whole networks. The proposed research will elucidate fundamental principles of neuronal circuits function and identify critical steps that initiate primary synaptic dysfunctions at the very early stages of sporadic AD.
Max ERC Funding
2 000 000 €
Duration
Start date: 2011-12-01, End date: 2017-09-30
Project acronym ABDESIGN
Project Computational design of novel protein function in antibodies
Researcher (PI) Sarel-Jacob Fleishman
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), LS1, ERC-2013-StG
Summary We propose to elucidate the structural design principles of naturally occurring antibody complementarity-determining regions (CDRs) and to computationally design novel antibody functions. Antibodies represent the most versatile known system for molecular recognition. Research has yielded many insights into antibody design principles and promising biotechnological and pharmaceutical applications. Still, our understanding of how CDRs encode specific loop conformations lags far behind our understanding of structure-function relationships in non-immunological scaffolds. Thus, design of antibodies from first principles has not been demonstrated. We propose a computational-experimental strategy to address this challenge. We will: (a) characterize the design principles and sequence elements that rigidify antibody CDRs. Natural antibody loops will be subjected to computational modeling, crystallography, and a combined in vitro evolution and deep-sequencing approach to isolate sequence features that rigidify loop backbones; (b) develop a novel computational-design strategy, which uses the >1000 solved structures of antibodies deposited in structure databases to realistically model CDRs and design them to recognize proteins that have not been co-crystallized with antibodies. For example, we will design novel antibodies targeting insulin, for which clinically useful diagnostics are needed. By accessing much larger sequence/structure spaces than are available to natural immune-system repertoires and experimental methods, computational antibody design could produce higher-specificity and higher-affinity binders, even to challenging targets; and (c) develop new strategies to program conformational change in CDRs, generating, e.g., the first allosteric antibodies. These will allow targeting, in principle, of any molecule, potentially revolutionizing how antibodies are generated for research and medicine, providing new insights on the design principles of protein functional sites.
Summary
We propose to elucidate the structural design principles of naturally occurring antibody complementarity-determining regions (CDRs) and to computationally design novel antibody functions. Antibodies represent the most versatile known system for molecular recognition. Research has yielded many insights into antibody design principles and promising biotechnological and pharmaceutical applications. Still, our understanding of how CDRs encode specific loop conformations lags far behind our understanding of structure-function relationships in non-immunological scaffolds. Thus, design of antibodies from first principles has not been demonstrated. We propose a computational-experimental strategy to address this challenge. We will: (a) characterize the design principles and sequence elements that rigidify antibody CDRs. Natural antibody loops will be subjected to computational modeling, crystallography, and a combined in vitro evolution and deep-sequencing approach to isolate sequence features that rigidify loop backbones; (b) develop a novel computational-design strategy, which uses the >1000 solved structures of antibodies deposited in structure databases to realistically model CDRs and design them to recognize proteins that have not been co-crystallized with antibodies. For example, we will design novel antibodies targeting insulin, for which clinically useful diagnostics are needed. By accessing much larger sequence/structure spaces than are available to natural immune-system repertoires and experimental methods, computational antibody design could produce higher-specificity and higher-affinity binders, even to challenging targets; and (c) develop new strategies to program conformational change in CDRs, generating, e.g., the first allosteric antibodies. These will allow targeting, in principle, of any molecule, potentially revolutionizing how antibodies are generated for research and medicine, providing new insights on the design principles of protein functional sites.
Max ERC Funding
1 499 930 €
Duration
Start date: 2013-09-01, End date: 2018-08-31
Project acronym ADDICTIONCIRCUITS
Project Drug addiction: molecular changes in reward and aversion circuits
Researcher (PI) Nils David Engblom
Host Institution (HI) LINKOPINGS UNIVERSITET
Call Details Starting Grant (StG), LS5, ERC-2010-StG_20091118
Summary Our affective and motivational state is important for our decisions, actions and quality of life. Many pathological conditions affect this state. For example, addictive drugs are hyperactivating the reward system and trigger a strong motivation for continued drug intake, whereas many somatic and psychiatric diseases lead to an aversive state, characterized by loss of motivation. I will study specific neural circuits and mechanisms underlying reward and aversion, and how pathological signaling in these systems can trigger relapse in drug addiction.
Given the important role of the dopaminergic neurons in the midbrain for many aspects of reward signaling, I will study how synaptic plasticity in these cells, and in their target neurons in the striatum, contribute to relapse in drug seeking. I will also study the circuits underlying aversion. Little is known about these circuits, but my hypothesis is that an important component of aversion is signaled by a specific neuronal population in the brainstem parabrachial nucleus, projecting to the central amygdala. We will test this hypothesis and also determine how this aversion circuit contributes to the persistence of addiction and to relapse.
To dissect this complicated system, I am developing new genetic methods for manipulating and visualizing specific functional circuits in the mouse brain. My unique combination of state-of-the-art competence in transgenics and cutting edge knowledge in the anatomy and functional organization of the circuits behind reward and aversion should allow me to decode these systems, linking discrete circuits to behavior.
Collectively, the results will indicate how signals encoding aversion and reward are integrated to control addictive behavior and they may identify novel avenues for treatment of drug addiction as well as aversion-related symptoms affecting patients with chronic inflammatory conditions and cancer.
Summary
Our affective and motivational state is important for our decisions, actions and quality of life. Many pathological conditions affect this state. For example, addictive drugs are hyperactivating the reward system and trigger a strong motivation for continued drug intake, whereas many somatic and psychiatric diseases lead to an aversive state, characterized by loss of motivation. I will study specific neural circuits and mechanisms underlying reward and aversion, and how pathological signaling in these systems can trigger relapse in drug addiction.
Given the important role of the dopaminergic neurons in the midbrain for many aspects of reward signaling, I will study how synaptic plasticity in these cells, and in their target neurons in the striatum, contribute to relapse in drug seeking. I will also study the circuits underlying aversion. Little is known about these circuits, but my hypothesis is that an important component of aversion is signaled by a specific neuronal population in the brainstem parabrachial nucleus, projecting to the central amygdala. We will test this hypothesis and also determine how this aversion circuit contributes to the persistence of addiction and to relapse.
To dissect this complicated system, I am developing new genetic methods for manipulating and visualizing specific functional circuits in the mouse brain. My unique combination of state-of-the-art competence in transgenics and cutting edge knowledge in the anatomy and functional organization of the circuits behind reward and aversion should allow me to decode these systems, linking discrete circuits to behavior.
Collectively, the results will indicate how signals encoding aversion and reward are integrated to control addictive behavior and they may identify novel avenues for treatment of drug addiction as well as aversion-related symptoms affecting patients with chronic inflammatory conditions and cancer.
Max ERC Funding
1 500 000 €
Duration
Start date: 2010-10-01, End date: 2015-09-30
Project acronym BrainInBrain
Project Neural circuits underlying complex brain function across animals - from conserved core concepts to specializations defining a species’ identity
Researcher (PI) Stanley HEINZE
Host Institution (HI) LUNDS UNIVERSITET
Call Details Starting Grant (StG), LS5, ERC-2016-STG
Summary The core function of all brains is to compute the current state of the world, compare it to the desired state of the world and select motor programs that drive behavior minimizing any mismatch. The circuits underlying these functions are the key to understand brains in general, but so far they are completely unknown. Three problems have hindered progress: 1) The animal’s desired state of the world is rarely known. 2) Most studies in simple models have focused on sensory driven, reflex-like processes, and not considered self-initiated behavior. 3) The circuits underlying complex behaviors in vertebrates are widely distributed, containing millions of neurons. With this proposal I aim at overcoming these problems using insects, whose tiny brains solve the same basic problems as our brains but with 100,000 times fewer cells. Moreover, the central complex, a single conserved brain region consisting of only a few thousand neurons, is crucial for sensory integration, motor control and state-dependent modulation, essentially being a ‘brain in the brain’. To simplify the problem further I will focus on navigation behavior. Here, the desired and actual states of the world are equal to the desired and current headings of the animal, with mismatches resulting in compensatory steering. I have previously shown how the central complex encodes the animal’s current heading. Now I will use behavioral training to generate animals with highly defined desired headings, and correlate neural activity with the animal’s ‘intentions’ and actions - at the level of identified neurons. To establish the involved conserved core circuitry valid across insects I will compare species with distinct lifestyles. Secondly, I will reveal how these circuits have evolved to account for each species’ unique ecology. The proposed work will provide a coherent framework to study key concepts of fundamental brain functions in unprecedented detail - using a single, conserved, but flexible neural circuit.
Summary
The core function of all brains is to compute the current state of the world, compare it to the desired state of the world and select motor programs that drive behavior minimizing any mismatch. The circuits underlying these functions are the key to understand brains in general, but so far they are completely unknown. Three problems have hindered progress: 1) The animal’s desired state of the world is rarely known. 2) Most studies in simple models have focused on sensory driven, reflex-like processes, and not considered self-initiated behavior. 3) The circuits underlying complex behaviors in vertebrates are widely distributed, containing millions of neurons. With this proposal I aim at overcoming these problems using insects, whose tiny brains solve the same basic problems as our brains but with 100,000 times fewer cells. Moreover, the central complex, a single conserved brain region consisting of only a few thousand neurons, is crucial for sensory integration, motor control and state-dependent modulation, essentially being a ‘brain in the brain’. To simplify the problem further I will focus on navigation behavior. Here, the desired and actual states of the world are equal to the desired and current headings of the animal, with mismatches resulting in compensatory steering. I have previously shown how the central complex encodes the animal’s current heading. Now I will use behavioral training to generate animals with highly defined desired headings, and correlate neural activity with the animal’s ‘intentions’ and actions - at the level of identified neurons. To establish the involved conserved core circuitry valid across insects I will compare species with distinct lifestyles. Secondly, I will reveal how these circuits have evolved to account for each species’ unique ecology. The proposed work will provide a coherent framework to study key concepts of fundamental brain functions in unprecedented detail - using a single, conserved, but flexible neural circuit.
Max ERC Funding
1 500 000 €
Duration
Start date: 2017-01-01, End date: 2021-12-31
Project acronym BRAINVISIONREHAB
Project ‘Seeing’ with the ears, hands and bionic eyes: from theories about brain organization to visual rehabilitation
Researcher (PI) Amir Amedi
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Call Details Starting Grant (StG), LS5, ERC-2012-StG_20111109
Summary My lab's work ranges from basic science, querying brain plasticity and sensory integration, to technological developments, allowing the blind to be more independent and even “see” using sounds and touch similar to bats and dolphins (a.k.a. Sensory Substitution Devices, SSDs), and back to applying these devices in research. We propose that, with proper training, any brain area or network can change the type of sensory input it uses to retrieve behaviorally task-relevant information within a matter of days. If this is true, it can have far reaching implications also for clinical rehabilitation. To achieve this, we are developing several innovative SSDs which encode the most crucial aspects of vision and increase their accessibility the blind, along with targeted, structured training protocols both in virtual environments and in real life. For instance, the “EyeMusic”, encodes colored complex images using pleasant musical scales and instruments, and the “EyeCane”, a palm-size cane, which encodes distance and depth in several directions accurately and efficiently. We provide preliminary but compelling evidence that following such training, SSDs can enable almost blind to recognize daily objects, colors, faces and facial expressions, read street signs, and aiding mobility and navigation. SSDs can also be used in conjunction with (any) invasive approach for visual rehabilitation. We are developing a novel hybrid Visual Rehabilitation Device which combines SSD and bionic eyes. In this set up, the SSDs is used in training the brain to “see” prior to surgery, in providing explanatory signal after surgery and in augmenting the capabilities of the bionic-eyes using information arriving from the same image. We will chart the dynamics of the plastic changes in the brain by performing unprecedented longitudinal Neuroimaging, Electrophysiological and Neurodisruptive approaches while individuals learn to ‘see’ using each of the visual rehabilitation approaches suggested here.
Summary
My lab's work ranges from basic science, querying brain plasticity and sensory integration, to technological developments, allowing the blind to be more independent and even “see” using sounds and touch similar to bats and dolphins (a.k.a. Sensory Substitution Devices, SSDs), and back to applying these devices in research. We propose that, with proper training, any brain area or network can change the type of sensory input it uses to retrieve behaviorally task-relevant information within a matter of days. If this is true, it can have far reaching implications also for clinical rehabilitation. To achieve this, we are developing several innovative SSDs which encode the most crucial aspects of vision and increase their accessibility the blind, along with targeted, structured training protocols both in virtual environments and in real life. For instance, the “EyeMusic”, encodes colored complex images using pleasant musical scales and instruments, and the “EyeCane”, a palm-size cane, which encodes distance and depth in several directions accurately and efficiently. We provide preliminary but compelling evidence that following such training, SSDs can enable almost blind to recognize daily objects, colors, faces and facial expressions, read street signs, and aiding mobility and navigation. SSDs can also be used in conjunction with (any) invasive approach for visual rehabilitation. We are developing a novel hybrid Visual Rehabilitation Device which combines SSD and bionic eyes. In this set up, the SSDs is used in training the brain to “see” prior to surgery, in providing explanatory signal after surgery and in augmenting the capabilities of the bionic-eyes using information arriving from the same image. We will chart the dynamics of the plastic changes in the brain by performing unprecedented longitudinal Neuroimaging, Electrophysiological and Neurodisruptive approaches while individuals learn to ‘see’ using each of the visual rehabilitation approaches suggested here.
Max ERC Funding
1 499 900 €
Duration
Start date: 2013-09-01, End date: 2018-08-31
Project acronym CaBiS
Project Chemistry and Biology in Synergy - Studies of hydrogenases using a combination of synthetic chemistry and biological tools
Researcher (PI) Gustav Oskar BERGGREN
Host Institution (HI) UPPSALA UNIVERSITET
Call Details Starting Grant (StG), LS1, ERC-2016-STG
Summary My proposal aims to take advantage of my ground-breaking finding that it is possible to mature, or activate, the [FeFe] hydrogenase enzyme (HydA) using synthetic mimics of its catalytic [2Fe] cofactor. (Berggren et al, Nature, 2013) We will now explore the chemistry and (bio-)technological potential of the enzyme using an interdisciplinary approach ranging from in vivo biochemical studies all the way to synthetic model chemistry. Hydrogenases catalyse the interconversion between protons and H2 with remarkable efficiency. Consequently, they are intensively studied as alternatives to Pt-catalysts for these reactions, and are arguably of high (bio-) technological importance in the light of a future “hydrogen society”.
The project involves the preparation of novel “artificial” hydrogenases with the primary aim of designing spectroscopic model systems via modification(s) of the organometallic [2Fe] subsite. In parallel we will prepare in vitro loaded forms of the maturase HydF and study its interaction with apo-HydA in order to further elucidate the maturation process of HydA. Moreover we will develop the techniques necessary for in vivo application of the artificial activation concept, thereby paving the way for a multitude of studies including the reactivity of artificial hydrogenases inside a living cell, but also e.g. gain-of-function studies in combination with metabolomics and proteomics. Inspired by our work on the artificial maturation system we will also draw from our knowledge of Nature’s [FeS] cluster proteins in order to prepare a novel class of “miniaturized hydrogenases” combining synthetic [4Fe4S] binding oligopeptides with [2Fe] cofactor model compounds.
Our interdisciplinary approach is particularly appealing as it not only provides further insight into hydrogenase chemistry and the maturation of metalloproteins, but also involves the development of novel tools and concepts applicable to the wider field of bioinorganic chemistry.
Summary
My proposal aims to take advantage of my ground-breaking finding that it is possible to mature, or activate, the [FeFe] hydrogenase enzyme (HydA) using synthetic mimics of its catalytic [2Fe] cofactor. (Berggren et al, Nature, 2013) We will now explore the chemistry and (bio-)technological potential of the enzyme using an interdisciplinary approach ranging from in vivo biochemical studies all the way to synthetic model chemistry. Hydrogenases catalyse the interconversion between protons and H2 with remarkable efficiency. Consequently, they are intensively studied as alternatives to Pt-catalysts for these reactions, and are arguably of high (bio-) technological importance in the light of a future “hydrogen society”.
The project involves the preparation of novel “artificial” hydrogenases with the primary aim of designing spectroscopic model systems via modification(s) of the organometallic [2Fe] subsite. In parallel we will prepare in vitro loaded forms of the maturase HydF and study its interaction with apo-HydA in order to further elucidate the maturation process of HydA. Moreover we will develop the techniques necessary for in vivo application of the artificial activation concept, thereby paving the way for a multitude of studies including the reactivity of artificial hydrogenases inside a living cell, but also e.g. gain-of-function studies in combination with metabolomics and proteomics. Inspired by our work on the artificial maturation system we will also draw from our knowledge of Nature’s [FeS] cluster proteins in order to prepare a novel class of “miniaturized hydrogenases” combining synthetic [4Fe4S] binding oligopeptides with [2Fe] cofactor model compounds.
Our interdisciplinary approach is particularly appealing as it not only provides further insight into hydrogenase chemistry and the maturation of metalloproteins, but also involves the development of novel tools and concepts applicable to the wider field of bioinorganic chemistry.
Max ERC Funding
1 494 880 €
Duration
Start date: 2017-02-01, End date: 2022-01-31
Project acronym ChemBioAP
Project Elucidation of autophagy using novel chemical probes
Researcher (PI) Yaowen Wu
Host Institution (HI) UMEA UNIVERSITET
Call Details Starting Grant (StG), LS1, ERC-2015-STG
Summary The interest on autophagy, an evolutionarily conserved process in eukaryotes, has enormously increased in the last years, since autophagy is involved in many diseases such as cancer and neurodegenerative disorders. Autophagosome formation is the key process in autophagy. Despite extensive work, the model of autophagosome formation is not yet well established. Some important questions on autophagosome biogenesis remain to be elusive, such as where the bona fide marker protein of autophagosome, LC3, is lipidated, how lipidated LC3 functions in autophagosome formation, and how the proteins for LC3 lipidation and delipidation are involved in autophagosome formation. Although genetic approaches have been useful to identify genes involved in autophagy, they are chronic and thereby the dynamics of phenotypic change cannot be followed, making them not suited for study highly dynamic process such as autophagosome formation. Herein, I propose to develop and use novel chemical probes to address these issues. First, I plan to prepare semi-synthetic caged LC3 proteins and apply them to monitor dynamics of autophagosome formation in the cell in order to address those questions on autophagosome formation. The semi-synthetic LC3 proteins are expected to confer a temporal control and to realize manipulation of protein structure, which renders such studies possible. Second, I intend to develop a versatile approach targeting specific endogenous proteins using a reversible chemically induced dimerization (CID) system, termed as “knock on and off” strategy. I plan to use this approach to elucidate the function of two distinct PI3K complexes in autophagosome formation. On one hand, the establishment of novel approaches will open up a new avenue for studying biological processes. On the other hand, the use of the tool will reveal the mechanism of autophagy.
Summary
The interest on autophagy, an evolutionarily conserved process in eukaryotes, has enormously increased in the last years, since autophagy is involved in many diseases such as cancer and neurodegenerative disorders. Autophagosome formation is the key process in autophagy. Despite extensive work, the model of autophagosome formation is not yet well established. Some important questions on autophagosome biogenesis remain to be elusive, such as where the bona fide marker protein of autophagosome, LC3, is lipidated, how lipidated LC3 functions in autophagosome formation, and how the proteins for LC3 lipidation and delipidation are involved in autophagosome formation. Although genetic approaches have been useful to identify genes involved in autophagy, they are chronic and thereby the dynamics of phenotypic change cannot be followed, making them not suited for study highly dynamic process such as autophagosome formation. Herein, I propose to develop and use novel chemical probes to address these issues. First, I plan to prepare semi-synthetic caged LC3 proteins and apply them to monitor dynamics of autophagosome formation in the cell in order to address those questions on autophagosome formation. The semi-synthetic LC3 proteins are expected to confer a temporal control and to realize manipulation of protein structure, which renders such studies possible. Second, I intend to develop a versatile approach targeting specific endogenous proteins using a reversible chemically induced dimerization (CID) system, termed as “knock on and off” strategy. I plan to use this approach to elucidate the function of two distinct PI3K complexes in autophagosome formation. On one hand, the establishment of novel approaches will open up a new avenue for studying biological processes. On the other hand, the use of the tool will reveal the mechanism of autophagy.
Max ERC Funding
1 500 000 €
Duration
Start date: 2016-09-01, End date: 2021-08-31
Project acronym CHEMOSENSORYCIRCUITS
Project Function of Chemosensory Circuits
Researcher (PI) Emre Yaksi
Host Institution (HI) NORGES TEKNISK-NATURVITENSKAPELIGE UNIVERSITET NTNU
Call Details Starting Grant (StG), LS5, ERC-2013-StG
Summary Smell and taste are the least studied of all senses. Very little is known about chemosensory information processing beyond the level of receptor neurons. Every morning we enjoy our coffee thanks to our brains ability to combine and process multiple sensory modalities. Meanwhile, we can still review a document on our desk by adjusting the weights of numerous sensory inputs that constantly bombard our brains. Yet, the smell of our coffee may remind us that pleasant weekend breakfast through associative learning and memory. In the proposed project we will explore the function and the architecture of neural circuits that are involved in olfactory and gustatory information processing, namely habenula and brainstem. Moreover we will investigate the fundamental principles underlying multimodal sensory integration and the neural basis of behavior in these highly conserved brain areas.
To achieve these goals we will take an innovative approach by combining two-photon calcium imaging, optogenetics and electrophysiology with the expanding genetic toolbox of a small vertebrate, the zebrafish. This pioneering approach will enable us to design new types of experiments that were unthinkable only a few years ago. Using this unique combination of methods, we will monitor and perturb the activity of functionally distinct elements of habenular and brainstem circuits, in vivo. The habenula and brainstem are important in mediating stress/anxiety and eating habits respectively. Therefore, understanding the neural computations in these brain regions is important for comprehending the neural mechanisms underlying psychological conditions related to anxiety and eating disorders. We anticipate that our results will go beyond chemical senses and contribute new insights to the understanding of how brain circuits work and interact with the sensory world to shape neural activity and behavioral outputs of animals.
Summary
Smell and taste are the least studied of all senses. Very little is known about chemosensory information processing beyond the level of receptor neurons. Every morning we enjoy our coffee thanks to our brains ability to combine and process multiple sensory modalities. Meanwhile, we can still review a document on our desk by adjusting the weights of numerous sensory inputs that constantly bombard our brains. Yet, the smell of our coffee may remind us that pleasant weekend breakfast through associative learning and memory. In the proposed project we will explore the function and the architecture of neural circuits that are involved in olfactory and gustatory information processing, namely habenula and brainstem. Moreover we will investigate the fundamental principles underlying multimodal sensory integration and the neural basis of behavior in these highly conserved brain areas.
To achieve these goals we will take an innovative approach by combining two-photon calcium imaging, optogenetics and electrophysiology with the expanding genetic toolbox of a small vertebrate, the zebrafish. This pioneering approach will enable us to design new types of experiments that were unthinkable only a few years ago. Using this unique combination of methods, we will monitor and perturb the activity of functionally distinct elements of habenular and brainstem circuits, in vivo. The habenula and brainstem are important in mediating stress/anxiety and eating habits respectively. Therefore, understanding the neural computations in these brain regions is important for comprehending the neural mechanisms underlying psychological conditions related to anxiety and eating disorders. We anticipate that our results will go beyond chemical senses and contribute new insights to the understanding of how brain circuits work and interact with the sensory world to shape neural activity and behavioral outputs of animals.
Max ERC Funding
1 499 471 €
Duration
Start date: 2014-04-01, End date: 2019-03-31
Project acronym ChromatinRemodelling
Project Single-Molecule And Structural Studies Of ATP-Dependent Chromatin Remodelling
Researcher (PI) Sebastian DEINDL
Host Institution (HI) UPPSALA UNIVERSITET
Call Details Starting Grant (StG), LS1, ERC-2016-STG
Summary The packaging of genetic information into chromatin regulates a wide range of vital processes that depend on direct access to the DNA template. Many chromatin-interacting complexes impact chromatin structure and their aberrant regulation or dysfunction has been implicated in various cancers and severe developmental disorders. A better understanding of the roles of chromatin-interacting complexes in such disease states requires a detailed mechanistic study. Many chromatin-interacting complexes modify chromatin structure, yet understanding the underlying mechanisms remains a major challenge in the field. Furthermore, how chromatin-interacting complexes are regulated to enable their various functions is incompletely understood. We will address these longstanding questions in two specific aims. Aim I: Building on our expertise in single-molecule biology, we will develop powerful single-molecule imaging approaches to monitor the action of chromatin-interacting complexes in real time. We will further probe how the diverse activities of the chromatin-associated complexes are coordinated and coupled to conformational transitions. Aim II: Drawing on our expertise in structural biology, we will use a range of structural techniques in combination with biochemical approaches to study the vital regulation of chromatin-interacting complexes by their regulatory subunits as well as by chromatin features. We expect to obtain ground-breaking insights into the mechanisms and regulation of disease-related chromatin-associated complexes, which may open up new horizons for developing therapeutic intervention strategies. Furthermore, the approaches developed here will enable the investigation of a large number of chromatin-related processes.
Summary
The packaging of genetic information into chromatin regulates a wide range of vital processes that depend on direct access to the DNA template. Many chromatin-interacting complexes impact chromatin structure and their aberrant regulation or dysfunction has been implicated in various cancers and severe developmental disorders. A better understanding of the roles of chromatin-interacting complexes in such disease states requires a detailed mechanistic study. Many chromatin-interacting complexes modify chromatin structure, yet understanding the underlying mechanisms remains a major challenge in the field. Furthermore, how chromatin-interacting complexes are regulated to enable their various functions is incompletely understood. We will address these longstanding questions in two specific aims. Aim I: Building on our expertise in single-molecule biology, we will develop powerful single-molecule imaging approaches to monitor the action of chromatin-interacting complexes in real time. We will further probe how the diverse activities of the chromatin-associated complexes are coordinated and coupled to conformational transitions. Aim II: Drawing on our expertise in structural biology, we will use a range of structural techniques in combination with biochemical approaches to study the vital regulation of chromatin-interacting complexes by their regulatory subunits as well as by chromatin features. We expect to obtain ground-breaking insights into the mechanisms and regulation of disease-related chromatin-associated complexes, which may open up new horizons for developing therapeutic intervention strategies. Furthermore, the approaches developed here will enable the investigation of a large number of chromatin-related processes.
Max ERC Funding
1 498 954 €
Duration
Start date: 2017-03-01, End date: 2022-02-28
