The role of the RNA regulon in the control of gene expression

Lead Research Organisation: MRC Toxicology Unit
Department Name: MRC Toxicology Unit

Abstract

Protein synthesis is the process by which the information in the genetic material in the cell, DNA, is converted via an intermediary substrate mRNA, into proteins. For proteins to be synthesised the mRNA must interact with a large complex called the ribosome which consists of RNAs and proteins. Ribosomes are able to decode the genetic information that is held in the mRNA and carry out the synthesis of the proteins. When mammalian cells are exposed to external agents that can damage the cell one of first things to happen is that protein synthesis is almost totally switched off. This is part of the cell's defensive mechanism since it allows the cell to repair the damage and recover from stress. However, whilst overall protein synthesis is decreased under these types of conditions, certain proteins still need to be made that allow the cell to recover from the damage. For example, we have shown that following treatment of cells with the type of UV-light that is found in sunlight, there is increased synthesis of proteins that are required to repair the damage that is caused to the DNA by this light. We have also found that under these conditions the cells use a different mechanism to synthesise proteins. However, data from other researchers have shown that under different conditions of cell stress e.g. when there is a reduced amount of oxygen present, different subsets of proteins are synthesised that are specific to the type of stress induced. This shows that there is coordinated regulation of protein synthesis following cell insult. The important question that needs to be addressed is how does this occur? Our results suggest that the mRNAs that are translated during cell stress contain important information in their non-coding regions (untranslated region UTR) that allows their recruitment to the ribosomes. In this proposal we aim analyse large amounts of data to identify the regions within the mRNAs that allow ribosome recruitment under different conditions of cell stress.

Technical Summary

Under conditions of patho-physiological cell stress post transcriptional regulation of gene expression is achieved by the reprogramming protein synthesis. For example, following exposure of cells to UV-light, hypoxic conditions and ER stress there is a general shut-down of protein synthesis which is mediated, in the most part, by a reduction in the levels of ternary complex. Under each of these situations there is selective recruitment to the ribosomes of mRNAs whose protein products are required as part of the response to the stress. For example, our data have shown that following exposure of cells to UV-light there is a selective increase in the polysomal association and corresponding synthesis of DNA repair enzymes. The key question that now needs to be addressed, that is fundamental to our understanding of post-transcriptional control of gene expression, is how selectivity is achieved. Two broad approaches will be used to answer this question. A detailed analysis of the components that comprise the post-transcriptional DNA damage response will be carried out by performing a range profiling studies to determine the mRNAs that remain polysomally associated following DNA damage, to identify and examine the RNA regulatory elements within their 5' and 3' UTRs, and determine the roles of key proteins in this response. An International Centre of Expertise will be established at Nottingham that will both coordinate post-transcriptional profiling data (generated in Nottingham and elsewhere) and provide access to others in the UK who are carrying out research in this area, but do not have access to the technology and/or expertise required. The data from these additional studies will also be subject to bioinformatics analysis and thus we will be in a unique position to extract the maximum amount of information from the data generated from these types of experiments, and to curate this information for the benefit of the UK (and world-wide) research community.

Publications

10 25 50
 
Description Protein synthesis is the process by which the information in the genetic material in the cell, the DNA, is
converted via an intermediary substrate, mRNA, into proteins. For proteins to be synthesised the mRNA must
interact with a large complex called the ribosome which consists of RNAs and proteins. Ribosomes can be thought
of as molecular factories where the genetic information that is held in the mRNA is decoded and then synthesised
into proteins. The amount of an individual protein that is made in a cell at any one time depends on how much of
the mRNA that encodes it binds to the ribosomes. In our work we have found that when a cell is exposed to agents
that will cause it to be damaged, such as too much sunlight, a group of mRNAs that code for the proteins which are
needed to repair the damage are all recruited to the ribosomes at the same time. This ensures all the proteins that
are required to repair the damage are present in the cell when they are needed. Importantly, we have shown that
this type of response occurs following exposure to many different chemicals and environmental agents and this
selective recruitment of mRNAs to the ribosome allows cell survival. We have also shown that it is possible to
modify this response to make cells more sensitive to certain chemicals such as the ones that are used to treat
cancers.
Exploitation Route A new way in which to stratify patients with ependymona for treatment with cisplatin.
Sectors Healthcare,Manufacturing, including Industrial Biotechology

 
Description Wellcome Trust collaborative award
Amount £2,000,000 (GBP)
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2016 
End 09/2021
 
Title TRANS PROF DB 
Description A data base for comparing data sets of the translatome 
Type Of Material Database/Collection of data 
Year Produced 2014 
Provided To Others? Yes  
Impact It will allow translational profiling data to be searched 
URL http://mrctools.mrctox.le.ac.uk/TRANS_PROF_DB
 
Description Brooke Priory school visit 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Type Of Presentation Workshop Facilitator
Geographic Reach Local
Primary Audience Schools
Results and Impact 30 children spent a day making DNA in the Unit.
They had 2 lectures one of which I presented

About half the children decided that they would like to be scientists but they were only 10!
Year(s) Of Engagement Activity 2012
 
Description School lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Paper Presentation
Geographic Reach Regional
Primary Audience Schools
Results and Impact Lecture on theory of knowledge and how scientific theories are developed to year 11 IB students

Increased appreciation of scientific thought.
Year(s) Of Engagement Activity 2012
 
Description Seminar Human Genetics Unit Edinburgh 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach National
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact MRC Human Genetics Unit, Edinburgh

Interest in work from colleagues
Year(s) Of Engagement Activity 2013
 
Description Seminar Queens University Belfast 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach National
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact September 24 - Centre for Cancer Research & Cell Biology, Queens University, Belfast.

Interest in research area
Year(s) Of Engagement Activity 2013
 
Description Seminar Sanquin Research 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Paper Presentation
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact 100 researchers attended talk. Seminar and Masterclass, Sanquin Research & Landsteiner Lab., Amsterdam

new collaborations
Year(s) Of Engagement Activity 2012,2013
 
Description Seminar UCL London 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact interest in research

Requests for further data
Year(s) Of Engagement Activity 2014
 
Description Seminar University of Surrey 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Type Of Presentation Keynote/Invited Speaker
Geographic Reach National
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact May 23 - Dept. of Microbiological & Cellular Sciences, University of Surrey

new collaborations
Year(s) Of Engagement Activity 2013
 
Description Seminar University of Tor Vergata Rome 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Pharmacy Summer School, University of Tor Vergata, Rome

Attended by students who showed interest in the research area
Year(s) Of Engagement Activity 2013
 
Description TV interview 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Gave TV interviews about the Unit's research to ITN, BBC East midlands todays, ITV Central, Sky News and Chanel 5 news.

Huge interest in the Unit's science from the public.
Year(s) Of Engagement Activity 2013
 
Description Unit Open day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Type Of Presentation Keynote/Invited Speaker
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Over 500 members of the pubic visited the Unit

Member of the public were very appreciative.
Students asked to come and carry out work experience in the Unit
Year(s) Of Engagement Activity 2013
 
Description conference Roscoff 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Paper Presentation
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Talk to colleagues,

new collaborations established
Year(s) Of Engagement Activity 2012