The role of actin in cell homeostasis

Lead Research Organisation: University of Sheffield
Department Name: Molecular Biology and Biotechnology

Abstract

Cells of all organisms receive signals that must be responded to. It is important for cells to co-ordinate different signalling pathways so they can perform their correct functions. Research in my laboratory uses a simple one-celled organism as a model system. Many processes are known to happen in the same way in this cell-type and in cells of more complex organisms such as mammals. We are particularly interested in the function of one protein called actin. Actin is part of a structure called the cytoskeleton (meaning cell skeleton) that helps give a cell its shape. Unlike a human skeleton however, actin is dynamic and constantly rearranging. We propose that this dynamic quality allows actin to act as a sensor of the cell environment to assess energy levels and whether the cell is under stress. If the environment is good, then cell processes can go ahead. If actin cannot function due to low energy or because it is modified by oxidants it can cause cells to enter a cell death pathway. While this is a fundamental cell biology problem, knowing how cells respond to stress impacts on our understanding of ageing and on disorders including neurodegeneration and cancer.

Technical Summary

The overall aims of my proposed research are to further our understanding of the role of actin in cells, and to determine how it functions to integrate essential processes to ensure cell survival or to trigger cell death.
Specifically, the research programme will-
-increase understanding of the mechanistic role of actin during endocyosis and determine how this interfaces with the specific cargo binding role of the Sla1 protein
-determine how the Gts1 protein that localises with actin patches in cells is able to control cell oscillations that are critical for co-ordinating temporal aspects of cell organisation
-determine how modifications in actin perturb its behaviour and lead to disease, ageing and cell death.
The proposed research is organised into three main areas as outlined by the objectives, and is based on results (mostly published) from studies conducted during my current fellowship. My previous studies and those from a number of other scientists incuding the Nobel Prize winner Paul Nurse, have shown that a relatively simple organism such as yeast can be extremely informative about fundamental cell processes. We will continue to exploit the genetic and proteomic advantages of budding yeast in these studies. In addition, I will initiate collaborative studies to increase use of mammalian tissue-culture cells and also developmental model systems in order to exploit our findings from yeast in directed studies on cells from more complex eukaryotes. One of the central methodologies that is used within my research is intracellular imaging and study of dynamics of cellular processes. This is one of the MRC current planning priorities and will continue to be an area of active study and development for the lab.
It is expected that a significant number of publications will arise from the proposed research and I will aim to publish in journals of high impact and repute in the field. I will also present my research at national and international meetings in order to disseminate our findings at a number of levels. The research will generate a number of new tools including strains and plasmids, as well as improved methodologies for certain assays. These will be sent, or communicated, to relevant individuals. While the research does not directly target therapeutics for specific diseases, knowledge gained from the programme could impact on research into sickle cell disease (actin modification) and neurodegenerative diseases (defects in endocytosis have been linked to Huntingdon‘s disease and early stage Alzheimers).

Publications

10 25 50
 
Description BBSRC Project Grant (Endocytic invagination and vesicle scission - interplay between dynamin homologues and amphiphysins in budding yeast)
Amount £259,404 (GBP)
Funding ID BB/G011001/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 10/2009 
End 10/2012
 
Description Pump priming grant
Amount £58,000 (GBP)
Organisation Yorkshire Cancer Research 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2010 
End 03/2011
 
Description Response Mode Funding Project Grant
Amount £850,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 01/2013 
End 01/2016
 
Description Response Mode Project Grant
Amount £602,000 (GBP)
Funding ID BB/J017094/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 11/2012 
End 10/2015
 
Title Yeast strains and plasmids 
Description >500 yeast stains and plasmids have been developed for research in the field. These are more robustly checked than commercially available strains 
Type Of Material Technology assay or reagent 
Year Produced 2006 
Provided To Others? Yes  
Impact Our own research output depend on these strains and all publications have used a number of these strains 
 
Description Durham Electron Microscopy 
Organisation Durham University
Department School of Biological and Biomedical Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution I have generated all the yeast strains and have driven the direction of the project
Collaborator Contribution Collaborators are performing of this project which require electron microscopy
Impact With MG (Durham) I have obtained a BBSRC project grant which was initiated 2009. Publication: Iwona I. Smaczynska-de Rooij Ellen G. Allwood, Soheil Aghamohammadzadeh, E. H. Hettema, Martin W. Goldberg, Kathryn R. Ayscough (2010) A Role for the Dynamin-like protein Vps1 during Endocytosis in Yeast. J.Cell Sci. 123 3496-3506
Start Year 2008
 
Description SH3yl-1 and Ysc84 
Organisation Agency for Science, Technology and Research (A*STAR)
Department Institute of Molecular and Cell Biology,
Country Singapore 
Sector Academic/University 
PI Contribution Providing tools and expertise on project. Sharing results from PhD project.
Collaborator Contribution expertise sharing. Collaborator is training person on grant in mammalian cell culture techniquesHave initiated collaboration to attempt structural analysis of protein of interest
Impact Obtained pump priming grant from YCR Obtained funding to support a PhD student on a joint project between University of Sheffield and IMCB Singapore. Publication: Robertson, A.S., Allwood, E.G., Smith, A.P., Gardiner, F.C., Costa, R., Winder, S.J. and Ayscough, K.R. (2009) The WASP homolog Las17 activates the novel actin-regulatory activity of Ysc84 to promote endocytosis in yeast. Mol. Biol. Cell. 20. 1618-1628
Start Year 2008
 
Description SH3yl-1 and Ysc84 
Organisation University of Sheffield
Department Department of Biomedical Science
Country United Kingdom 
Sector Academic/University 
PI Contribution Providing tools and expertise on project. Sharing results from PhD project.
Collaborator Contribution expertise sharing. Collaborator is training person on grant in mammalian cell culture techniquesHave initiated collaboration to attempt structural analysis of protein of interest
Impact Obtained pump priming grant from YCR Obtained funding to support a PhD student on a joint project between University of Sheffield and IMCB Singapore. Publication: Robertson, A.S., Allwood, E.G., Smith, A.P., Gardiner, F.C., Costa, R., Winder, S.J. and Ayscough, K.R. (2009) The WASP homolog Las17 activates the novel actin-regulatory activity of Ysc84 to promote endocytosis in yeast. Mol. Biol. Cell. 20. 1618-1628
Start Year 2008
 
Description School visit, Sheffield 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact A DNA and Cells Workshop was organised for 90 Y6 (age 10-11) children. It was undertaken by 3 PIs and PhD student helpers. The workshop took 2.5 hours and involved 7 distinct activities.

Feedback forms were completed by >90% of children with >95% indicating a high level of interest in the workshop.
Year(s) Of Engagement Activity 2011
 
Description School visit. Sheffield 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact On the latest visit 90 pupils listened to a short talk about microbes and then investigated the presence of bacteria on their hands and the effect of handwashing on this.

This workshop has been run by myself in all of the years indicated and also by postdocs in different local schools including widening participation schools

School keen to repeat and broaden activity. Neighbouring school also interested in liaising more closely with scientists.
Year(s) Of Engagement Activity 2006,2008,2010,2011,2012