Please join us for the April PPSG Early Career Academic seminar series. The speakers will be Dr Roman Belle from Newcastle University and Dr Richard Obexer from the University of Manchester.
Dr Roman Belle – Newcastle University
https://kawamuraresearchgroup.com/members/roman-belle
Title: Exploring Chemical Tools for Nε-methyl-lysine Chromatin Binding Modules: Insights into Recognition and Chromatin Dynamics
Abstract: In eukaryotes, histones undergo a plethora of different post-translational modifications (PTMs), including phosphorylation, acetylation, and methylation. Lysine methylation is a common and dynamic PTM that is introduced by histone methyltransferases (writers), removed by histone lysine demethylases (erasers), and ‘read’ by chromatin binding modules (readers) to elicit a biological response. The modification is intricately linked with transcriptional regulation, cellular differentiation, and chromatin structure; however, its biological function depends on the location within the nucleosome complex and combinatorial context. Dysregulation thereof can have profound implications for health and disease, yet our understanding remains incomplete. While chemical probes have been instrumental in elucidating the functional role of histone lysine methyltransferases and demethylases, there is a dearth of potent and target-specific inhibitors / probes available for Nε-methyl lysine readers. In this presentation, recent advancements in chemical tools aimed at studying these readers are explored. A series of synthetic histone peptides, containing Nε-trimethyl lysine derivatives, were cross-examined against histone Nε-methyl lysine readers for their binding affinity using isothermal titration calorimetry (ITC). The results highlight the importance of methylation for a strong binding affinity and reveal that a stronger binding affinity, beyond Nε-trimethyl lysine, can be engineered. Furthermore, we demonstrate that allosteric activation of histone lysine demethylases, using these chemical tools, can be achieved, opening new avenues for understanding chromatin dynamics and potential therapeutic interventions.
Dr Richard Obexer - University of Manchester
Title: Engineering artificial organelles by liquid-liquid phase separation using de novo peptides
Abstract: Membraneless organelles are biomolecular condensates that play important roles in various cellular processes. Their design and engineering is a major challenge in synthetic biology and biotechnology. To date, artificial organelles have been mostly designed and engineered from structurally well-defined protein assemblies. However, over the last decade, liquid-liquid phase separation (LLPS) has emerged as a major principle for organising the cytoplasm of cells. Our goal was to recreate such assemblies by design from first principles in order to create liquid-like artificial organelles.1 By connecting amphipathic helices via an intrinsically disordered linker and tuning helix-helix interactions, we created an artificial peptide tag (HERD-2.2), which allowed formation of protein condensates in E. coli cells with properties that are consistent with the hallmarks of LLPS. Furthermore, these condensates were functionalised through co-localisation of an enzymatic cascade for indigo production. Overall, we could demonstrate the superior cascade efficiency of liquid organelles over gel-like condensates or protein aggregates.
References:
[1] Hilditch, A.T. et al. Nat. Chem. 2024, 16, 89.
If you would like to present in future seminars, please contact one of the organisers. We welcome presentations from early career UK-based academics or senior postdoctoral researchers seeking to establish an independent career in peptide and protein science.
Louis Luk: lukly@cardiff.ac.uk
Chris Coxon: chris.coxon@ed.ac.uk
Louise Walport: louise.walport@crick.ac.uk
Dr Roman Belle – Newcastle University
https://kawamuraresearchgroup.com/members/roman-belle
Title: Exploring Chemical Tools for Nε-methyl-lysine Chromatin Binding Modules: Insights into Recognition and Chromatin Dynamics
Abstract: In eukaryotes, histones undergo a plethora of different post-translational modifications (PTMs), including phosphorylation, acetylation, and methylation. Lysine methylation is a common and dynamic PTM that is introduced by histone methyltransferases (writers), removed by histone lysine demethylases (erasers), and ‘read’ by chromatin binding modules (readers) to elicit a biological response. The modification is intricately linked with transcriptional regulation, cellular differentiation, and chromatin structure; however, its biological function depends on the location within the nucleosome complex and combinatorial context. Dysregulation thereof can have profound implications for health and disease, yet our understanding remains incomplete. While chemical probes have been instrumental in elucidating the functional role of histone lysine methyltransferases and demethylases, there is a dearth of potent and target-specific inhibitors / probes available for Nε-methyl lysine readers. In this presentation, recent advancements in chemical tools aimed at studying these readers are explored. A series of synthetic histone peptides, containing Nε-trimethyl lysine derivatives, were cross-examined against histone Nε-methyl lysine readers for their binding affinity using isothermal titration calorimetry (ITC). The results highlight the importance of methylation for a strong binding affinity and reveal that a stronger binding affinity, beyond Nε-trimethyl lysine, can be engineered. Furthermore, we demonstrate that allosteric activation of histone lysine demethylases, using these chemical tools, can be achieved, opening new avenues for understanding chromatin dynamics and potential therapeutic interventions.
Dr Richard Obexer - University of Manchester
Title: Engineering artificial organelles by liquid-liquid phase separation using de novo peptides
Abstract: Membraneless organelles are biomolecular condensates that play important roles in various cellular processes. Their design and engineering is a major challenge in synthetic biology and biotechnology. To date, artificial organelles have been mostly designed and engineered from structurally well-defined protein assemblies. However, over the last decade, liquid-liquid phase separation (LLPS) has emerged as a major principle for organising the cytoplasm of cells. Our goal was to recreate such assemblies by design from first principles in order to create liquid-like artificial organelles.1 By connecting amphipathic helices via an intrinsically disordered linker and tuning helix-helix interactions, we created an artificial peptide tag (HERD-2.2), which allowed formation of protein condensates in E. coli cells with properties that are consistent with the hallmarks of LLPS. Furthermore, these condensates were functionalised through co-localisation of an enzymatic cascade for indigo production. Overall, we could demonstrate the superior cascade efficiency of liquid organelles over gel-like condensates or protein aggregates.
References:
[1] Hilditch, A.T. et al. Nat. Chem. 2024, 16, 89.
If you would like to present in future seminars, please contact one of the organisers. We welcome presentations from early career UK-based academics or senior postdoctoral researchers seeking to establish an independent career in peptide and protein science.
Louis Luk: lukly@cardiff.ac.uk
Chris Coxon: chris.coxon@ed.ac.uk
Louise Walport: louise.walport@crick.ac.uk
