Dr Christoph Engl

Profile

Education

• 2010 PhD in Biology, Imperial College London, UK
• 2004 German University Diploma in Biology, University of Regensburg, Germany

Awards & Honours

• 2023 Elected Member of the Royal Society of Biology (MRSB)
• 2020 Fellow of the Higher Education Academy UK (FHEA)
• 2020 Queen Mary ADEPT Fellow, Queen Mary University of London
• 2015 Queen’s Fellow, Queen’s University Belfast
• 2014 Faculty of Natural Sciences Award for Support of Excellence in Teaching, Imperial College London
• 2005 Faculty of Life Sciences PhD Studentship, Imperial College London 

Research

Research in the lab of Dr Engl aims to uncover how bacteria communicate with, adapt to, and shape their environment; with a particular emphasis on Sigma54-regulated systems. We combine cellular, molecular, systems, ecology and state-of-the-art imaging techniques to address fundamental questions in bacterial cell physiology. The overall objective is to advance our understanding in this field to help address major societal challenges such as antimicrobial resistance and sustainability.

Current interests focus on decision-making of individual bacterial cells and on post-transcriptional RNA processing.

Editorial Roles

• 2023 Associate Editor at Frontiers in Microbiology 
• 2022-23 Review Editor at Frontiers in Microbiology 

Teaching

Dr Engl is a Senior Lecturer in Microbiology, Programme Director of the MSc Biomedical Sciences and Fellow of the Higher Education Academy UK. He has been teaching undergraduate and postgraduate students since 2012. 

Dr Engl received an award for Support for Excellence in Teaching from the Faculty of Life Sciences at Imperial College London and he was nominated by his students for a Student Academic Choice Award from the Imperial College’s Union.

At Queen Mary, Dr Engl teaches on the following modules:

BMD100 Essential Skills for Biomedical Scientists

BMD117 The Microbial World and Humans

BIO231 Microbial Physiology and Growth

BMD600 Research Project (BSc Biomedical Sciences)

BMD606 Engaging the Public with Science

BMD700P Research project (MSc Biomedical Sciences)

BMD701P Literature Review for Research project (MSc Biomedical Sciences)

Alongside his teaching commitments Dr Engl is also:

Chair of the Exam Board for UG Biomedical Sciences

Research

Research Interests:

The majority of Dr Engl’s research has centred around adaptive responses involving Sigma54 (s⁵⁴), a factor that directs RNA polymerase (RNAP) to its cognate promoters. Analogous to eukaryotic systems, Sigma54-dependent transcription initiation strictly requires mechano-chemical energy for the remodelling of the closed to the open promoter complex. This is achieved through ATP hydrolysis by an activator protein that binds to enhancer sequences ~100 nucleotides upstream of the promoter DNA. The enhancer-bound activator is brought into close proximity to the RNAP-s⁵⁴ holoenzyme through DNA bending via a protein called Integration Host Factor (IHF). The ability of the activator to hydrolyse ATP is tightly regulated. Bacterial cells can encode multiple activators whereby each activator drives the transcription of an adaptive response to a specific stimulus. Sigma54-regulated systems have been identified in the majority of bacterial species. They control important physiological processes including nitrogen fixation and the delivery of virulence factors into host cells by plant and animal pathogens.

Current Research

Transcription dynamics in individual bacterial cells

One of the best studied Sigma54-regulated systems is the Psp response which maintains proton motive force under membrane stress. Dr Engl has revealed the regulation, spatio-temporal dynamics and stoichiometry of key Psp proteins in live bacterial cells. Recently Dr Engl has utilised the RNA FISH technique to visualise psp mRNA in individual bacterial cells, enabling the determination of the single-cell kinetics and population heterogeneity of Sigma54-regulated transcription. He could demonstrate that the mode of transcriptional bursting is determined by the route to transcription initiation (Engl et al 2020). He could also show that the burst kinetics of Sigma54-regulated promoters resemble those of enhancer-dependent promoters in higher organisms (Engl et al 2020). In collaboration with Prof Mullineaux from the Department of Biochemistry at QMUL, he has further applied RNA FISH to reveal the subcellular localisation of mRNAs encoding proteins of the photosynthetic apparatus in cyanobacteria (Mahbub et al 2020).

Dr Engl currently uses single cell and single molecule fluorescence imaging to study cell-to-cell heterogeneity and population dynamics associated with other molecular switches that drive key adaptive responses in bacteria.

Post-transcriptional RNA processing

Another Sigma54-regulated system studied by Dr Engl is Rtc from E. coli. RtcA (a RNA cyclase) and RtcB (an RNA ligase) encode an RNA-end healing and sealing mechanism that is involved in post-transcriptional RNA processing. Dr Engl could show that the Rtc system helps to maintain the homeostasis of the bacterial ribosome under nutritional stress (Engl et al 2016). The ribosome translates genetic information within mRNA into proteins; it thus provides essential building blocks of the cell. Maintaining ribosome function under fluctuating and challenging environmental conditions is therefore critical for bacteria to thrive. Ribosomes from bacteria and eukaryotes differ, enabling targeted interference with ribosome function as a means to halt bacterial growth. Hence, the ribosome is the target of the majority of antimicrobials currently used in clinical and agricultural settings. Strikingly, the Rtc system is induced by and increases the tolerance to antimicrobials that specifically target the ribosome (Engl et al 2016). As such, Rtc represents a physiological response to antimicrobials that was previously overlooked. How it increases the tolerance to ribosome targeting antimicrobials is currently unknown. Dr Engl is therefore continuing his investigation into post-transcriptional RNA processing by Rtc.

Research Funding

Research in the Engl lab is funded by grants from the Wellcome Trust and the Leverhulme Trust. 

Publications

Selected publications (*corresponding authorship)

Kotta-Loizou I, Giuliano MG, Jovanovic M, Schaefer J, Ye F, Zhang N, Irakleidi DA, Liu X, Zhang X, Buck M, Engl C* (2022) The RNA repair proteins RtcAB regulate transcription activator RtcR via its CRISPR-associated Rossmann fold domain. iScience 25: 105425.

Bashir T, Brackston RD, Waite C, Kotta-Loizou I, Carey MR, Engl C, Buck M, Schumacher J (2022) Molecular Origins of Transcriptional Heterogeneity in Diazotrophic Klebsiella oxytoca. mSystems 7: e0059622.

Engl C*, Jovanovic G, Brackston RD, Kotta-Loizou I, Buck M (2020) The route to transcription initiation determines the mode of transcriptional bursting in bacteria. Nature Communications 11: 1-11.

Mahbub M, Hemm L, Yang Y, Kaur R, Carmen H, Engl C, Huokko T, Riediger M, Watanabe S, Liu L-N, Wilde A, Hess W, Mullineaux CW (2020) mRNA localisation, reaction centre biogenesis and thylakoid membrane targeting in cyanobacteria. Nature Plants 6: 1179-1191.

Engl C* (2019) Noise in bacterial gene expression. Biochem Soc Trans 47: 209-217.

Finch EA, Caruso T, Engl C* (2018) Effects of Paenibacillus polymyxa inoculation on below-ground nematode communities and plant growth. Soil Biol Biochem 121: 1-7.

Engl C*, Schaefer J, Kotta-Loizou I, Buck M. (2016) Cellular and molecular phenotypes depending upon the RNA repair system RtcAB in Escherichia coli. Nucleic Acids Research 44: 9933-9941.

Schaefer J, Engl C*, Zhang N, Lawton E, Buck M (2015) Genome wide interactions of wild-type and activator bypass forms of σ54. Nucleic Acids Research 43: 7280-91.

Supervision

Postdoctoral Researchers 

• Dr Nida Ali

Current PhD students:

• Danylo Gorenkin (co-supervision with Dr Aravindan Ilangovan)
• Shafagh Moradian
• Zechuan Gong

 

Public Engagement

Dr Engl co-organised the following public event:

Microbes: The Good, the Bad and the Ugly (with Dr Adam Rutherford & Guests)

Public lectures on how microorganisms change our world

Northern Ireland Science Festival 2017

Audience >100, Age 14+