Mechanisms of autophagy regulation by the Fat/Hippo pathway

Lead Research Organisation: King's College London
Department Name: MRC Ctr for Developmental Neurobiology

Abstract

Neurodegenerative diseases are currently one of the top medical priorities. It is essential to understand the mechanisms through which the nerve cells (neurons) degenerate, to be able to design advanced therapies for protecting the cells. The process of autophagy, self-digestion, is of vital importance for human health in ageing and neurodgeneration. Autophagy is known to help neurons in keeping healthy through degradation of old and not functional cell components. We have discovered that new group of genes, acting in a pathway (the Fat/Hippo pathway), which is best known for its effects on cancer, is also essential for correct autophagy and neuronal health. We now wish to investigate the mechanism through which the Fat/Hippo pathway affects autophagy, so that new intelligent approaches can be designed for alleviating neurodegeneration by modulating the activity of this pathway.

Technical Summary

Neurodegenerative diseases represent a significant human, societal and economic burden, and are a research priority in the biomedical sciences. Autophagy, a lysosomal catabolic process that disposes of unhealthy proteins and organelles, is currently considered essential for the development and progression of most neurodegenerative pathologies. Through advanced functional genomic studies in a Drosophila model for the neurodegenerative disease Dentatorubral-pallidoluysian atrophy, we have identified the tumour suppressor Fat and the growth control Hippo pathway as essential for neuronal homeostasis via autophagy. We have established that its effect in neuroprotection is not a secondary consequence of proliferation control. Rather, we report that the Fat/Hippo pathway critically affects autophagy and cell size in neurons. We now plan to study the mechanisms through which the Fat/Hippo pathway impacts on autophagy, in developing and adult post-mitotic neurons. In particular we will establish its intersection with the Tor pathway, known to be a key regulator of both autophagy and cell size, and thus a natural candidate for interacting with the Fat/Hippo pathway in this system.
Having pioneered the role of the Fat/Hippo pathway in neurodegeneration, we are ideally placed to perform these studies now, in a very supportive world-renown centre of excellence for neuroscience.
The proposed research will have an important biomedical impact, as it will establish the action of the Fat/Hippo pathway, an entirely new player in autophagy and neuronal homeostasis that can be potentially involved in several neurodegenerative conditions.
 
Description KMRT JRC studentship
Amount £78,450 (GBP)
Funding ID 3/2013 
Organisation King's College London 
Sector Academic/University
Country United Kingdom
Start 08/2013 
End 07/2016
 
Description Pilot project
Amount £28,230 (GBP)
Funding ID ARUK-PPG2017B-018 
Organisation Alzheimer's Research UK 
Department Alzheimers Research UK, Cambridge
Sector Charity/Non Profit
Country United Kingdom
Start 03/2018 
End 08/2018
 
Description Research Grant
Amount £111,000 (GBP)
Funding ID 20121109 
Organisation The Henry Smith Charity 
Sector Charity/Non Profit
Country United Kingdom
Start 12/2012 
End 12/2015
 
Description Research Grant
Amount £125,421 (GBP)
Funding ID 855-791 
Organisation Motor Neurone Disease Association (MND) 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2017 
End 08/2019
 
Description Reserach Grant
Amount £197,000 (GBP)
Funding ID GN2446 
Organisation Action Medical Research 
Sector Charity/Non Profit
Country United Kingdom
Start 03/2016 
End 03/2019
 
Title Atg13 phosphomutants 
Description Drosophila transgenic lines for phosphorylation mutations in Atg13 
Type Of Material Model of mechanisms or symptoms - non-mammalian in vivo 
Provided To Others? No  
Impact These transgenic Drosophila will allow us to detect the physiological relevance of the phosphorylations detected in Atg13 upon Hpo kinase activity 
 
Title BAP-BirA for autophagy 
Description New method to detect autophagosomes based on in vivo biotynilation in Drosophila cells and flies 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact We have dtetcted biotynilated autophagosomes in BG3 Drosophila neuronal cells and have generated transgenic flies. 
URL http://www.kcl.ac.uk
 
Title Hpo stable BG3 cells 
Description Drosophila neuronal BG3 cells expressing stably Hpo and Atg13 to detect the first step of autophagy regulation 
Type Of Material Cell line 
Provided To Others? No  
Impact Using this cell lines we have demonstrated that Hpo promotes Atg13 phosphorylation independently of Tor, providing one mechansim for regulation of autophagy by the Hpo pathway 
URL http://www.kcl.ac.uk
 
Title anti-Atro 
Description We have generated in collaboration with ABMART a monoclonal mouse anti-Atro Ab that works for for WB, IF and ChIP 
Type Of Material Antibody 
Year Produced 2013 
Provided To Others? Yes  
Impact We are now able to study and localise Atrophin with a reliable antibody. A whole genome CHIP has been performed using this antibody and we have published this in a paper on the journal e-Life. 
URL http://www.kcl.ac.uk
 
Title Phosphoproteomic analysis of Atg13 
Description Collection of phosphopeptides from Atg13 as determined by Mass Spectrometry 
Type Of Material Database/Collection of data 
Provided To Others? No  
Impact We have identified the phosphorylation sites in Atg13 controlled by Hpo 
URL Http://www.kcl.ac.uk
 
Description BAP-BirA Burrone 
Organisation King's College London
Department MRC Centre for Developmental Neurobiology
Country United Kingdom 
Sector Academic/University 
PI Contribution We have used the Bap/BirA system to engineer reagents in Drosophila to detect autophagy
Collaborator Contribution Has provided the Bap and BirA DNA
Impact Generation of transgenic animals and of plasmids for cell cultrue work in Drosophila using the BAP/BirA system to detect autophagy
Start Year 2011
 
Description Mst1 kinase assay 
Organisation Francis Crick Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution We have provided the fly Atg13 cDNA for expressing and purifying the protein for an in-vitro kinase assay
Collaborator Contribution Dr. Sila Ultanir, will use her modified Mst-1 to assess whether this phosphorylates directly in vitro Atg13, contributing to a paper of our under revision.
Impact Established a non direct phosphorylation
Start Year 2015
 
Description STK38/Trc 
Organisation Curie Institute Paris (Institut Curie)
Department Transduction Networks Analysis Group
Country France 
Sector Academic/University 
PI Contribution WE have demonstrated that Trc, the Drosophila orthologue of STK38 is necessary and sufficient for autophagy in Drosophila
Collaborator Contribution They have demonstrated that mammalian Mst1, Mst2 and Mst3 are capable of increasing Atg13 phosphorylation in cells.
Impact Conservation of signalling between Drosophila and mammals
Start Year 2013
 
Description TrcAtg8 
Organisation University of Warwick
Department School of Life Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution We have demonstrated colocalisation between Trc and Atg8
Collaborator Contribution They have demonstrated protein-protein binding between Trc and Atg8
Impact none yet
Start Year 2017
 
Description Vici Syndrome Epg5 
Organisation Guy's and St Thomas' NHS Foundation Trust
Country United Kingdom 
Sector Public 
PI Contribution We have started a collaboration with Dr. Heinz Jungbluth, a neurologist, to look investigate the possibility that the Epg5 gene responsible for Vici Syndrome is part of, or interact with the Hpo pathway, given the similarity of phenotypes.
Collaborator Contribution Dr. Jungbluth, has revealed unpublished knowledge about Epg5 and other genes involved in the Vici Syndrome
Impact The collaboration has led to us analyising the autophagy and neurodegenerative features of Epg5 mutants in Drosophila. The collaboration is multidisciplinary as we collaborate with a clinical partner and we are planning common applications to fund our research.
Start Year 2014
 
Description In2ScienceUK 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Schools
Results and Impact 1 "free-meal" student attended the lab for 2 weeks and prepared a written report about his visit

students apply to medical and science degrees at universities having being advantaged by direct research experience
Year(s) Of Engagement Activity 2012,2013,2014,2015
 
Description Secondary and gap year students 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Hosting from two weeks to 3months secondary school pupils from different locations, North London Collegiate Shcool, the Judd School in Kent and IMIBERG school in Bergamo, Italy

enhanced interest in biomedical science university degree
Year(s) Of Engagement Activity 2013,2015