Marie-Louise Francis


Personal photo - Marie-Louise Francis

Marie-Louise Francis

Doctoral Student at the

Rex Richards Building, South Parks Road, Oxford OX1 3QU

Education


Interests

My main research interests within Biochemistry are in protein structure and functional studies, protein-protein interactions, mechanisms and pathways, Bacterial pathogenesis, virulence and secretion systems

Current work

My first rotation project is in the laboratory of Dr Catherine Green and Dr Sergi-Padilla Parra at the Wellcome Trust Centre for Human Genetics, Monday 26th January 2014 - Friday 17th April 2015.This project will implement a novel quantitative imaging method utilizing Forster resonance energy transfer (FRET) and fluorescence lifetime imaging (FLIM) to detect and quantify protein-protein interactions in living cells. The aim is to apply this technique to the analysis of transient and regulated protein contacts occurring at DNA replication forks in human cells. The new G-FLIM technique will be applied to the study of protein interactions at DNA replication forks in unperturbed living cells and also under conditions of replication stress, such as found in tumor cells or in cell treated with chemotherapeutic agents.

Previous research

  • ERASMUS 12 month Industrial Placement Project, Institut Pasteur, Paris- September 2011-September 2012 During my time at Keele, I had the opportunity to undertake a 12 month Industrial ERASMUS placement and was fortunate enough to secure a place at the Pasteur Institute in Paris. I worked in the Gram-negative bacterial membrane laboratory of Professor Cecile Wandersman. The project concerned investigating the secretion of the haemophore HasA protein from the Gram-negative bacteria Serratia marcescens, to the extracellular medium via the Type 1 Secretion System (T1SS). HasA possesses anchoring sequences throughout the polypeptide that bind to its inner membrane ATP Binding Cassette (ABC) protein. These sequences drive the T1SS tripartite complex assembly, maintain its integrity and maximise haemophore secretion. The project entailed further characterisation of the anchoring sequences of HasA by exploring secretion efficiency and protein stability of single and multiple mutants of HasA and HasA mutant interaction with HasD IM ABC protein. A range of genetic, biochemical and microbiological techniques were used to investigate this.

  • OXION Proteomics Wellcome Trust funded Vacation Studentship, University of Oxford- 13 th May-5 th July 2013 During the summer following the completion of my undergraduate degree, I undertook an 8-week Oxion Proteomics Wellcome Trust funded Vacation Studentship in the DPAG department at the University of Oxford with Dr Holger Kramer. The project involved chemical protein cross-linking in combination with tandem mass spectrometric analysis, to obtain structural information from proteins in solution. Techniques used included protein cross-linking, proteolytic digestion, enrichment, mass spectrometric analysis, database searching and data interpretation for the identification of peptide sequences involved in the cross-links.

  • Masters of Science by Research (MRes) Project- September 2013-September 2014 I have recently completed a 12 month Masters of Science by Research (MRes) degree in Biochemistry at the University of Oxford, in the Laboratory of Professor Colin Kleanthous. My project involved characterising the structural and mechanistic basis of anti-sigma factor inhibition of bacterial sigma factors. I worked with SigR and RsrA from the Gram-positive bacterium Streptomyces coelicolor. SigR is an ECF sigma factor responsible for the transcription of genes involved in the regulation of cytosolic redox homoeostasis, in response to oxidative stress within the cytosol. To prevent continuous transcription it has its activity regulated by RsrA anti-sigma factor. The project involved determining the thermodynamics of the complex using Isothermal titration calorimetry and development of a fluorescence-based assay to determine the kinetics of SigR-RsrA complex formation using stopped-flow. Techniques used included biochemical mutagenesis and protein purification, biophysical characterisation through ITC, steady-state Tryptophan Fluorescence emission quenching, Circular Dichroism and pre-steady-state fluorescence stopped-flow.