Andrew Hudson

Short Biography

Andrew Hudson is Professor of Biophysical Chemistry at the School of Chemistry at the University of Leicester, specialising in applying optical methods to address problems at the life science interface. His working group uses methods such as spectroscopy, imaging, photonics and microfluidics to investigate e.g., the dynamics of single molecules and to quantify the distribution of haem proteins in living cells. His research group has also developed new fluorescence assays to probe the role of haem in the molecular mechanism of the transcription-translation feedback loops which are responsible for maintaining circadian rhythms.

Prof. Hudson obtained his Bachelor’s degree in Chemistry from the University of Oxford. He earned his doctorate degree in Chemical Physics from the University of Toronto in 1998, while working with Professor John Polanyi FRS. After gaining experience in the optical technologies industry, he returned to academia in 2005 and established an independent research group at the University of Leicester in 2008.

AMBER postdoctoral fellowship subject (second call)

Project 1: Unravelling the mechanism by which haem modulates the activity of transcription factors

It is becoming clear that the cell biology of haem is wider than its role as a prosthetic group in housekeeping proteins[11]. Haem might not always be inextricably linked to a host, or pivotal to a protein’s functional activity. One example is its ability to modulate the behaviour of transcription factors, such as those that generate the internal-timekeeping system of the mammalian-molecular clock. This type of haem-protein interaction must be transient and reversible, in contrast to the tight binding of a prosthetic group. Whilst certain sequences of amino acids have been implicated as haem-recognition motifs, there is still uncertainty about how haem binds to transcription factors. The reversible nature of the interaction suggests that the binding sites must be altogether different to the binding pockets in haemoproteins. The binding of haem to the transcription factor can be expected to induce a significant conformational change which might prevent its association to DNA (or cause an existing DNA-protein complex to dissociate). In addition, as a consequence of the toxicity of free molecules of haem, we must assume that transcription factors acquire haem via ligand-substitution reactions[3] from a chaperone; a protein that is suspected to moonlight as a haem chaperone is GAPDH[2]. This project will investigate transient haem-protein interactions by utilizing structural biology to reveal the ligand-binding site, and different biophysical approaches to reveal the conformational dynamics of the transition between the apo and holo protein, along with mechanistic detail of haem-substitution reactions from an exemplar chaperone, GAPDH to an acceptor protein. 

 Project leadership team: Hanna Kwon (University of Leicester), Andrew Hudson (University of Leicester), Peter Moody University of Leicester). Co-investigator: Kajsa Sigfridsson Clauss (MAX IV laboratory). Collaborators: Charalambos Kyriacou (University of Leicester), Ezio Rosato (University of Leicester), Emma Raven (University of Bristol)

1. Basran, J., et al., Binding of l-kynurenine to X. campestris tryptophan 2,3-dioxygenase. J Inorg Biochem, 2021. 225: p. 111604.

2. Biswas, P., Y. Dai, and D.J. Stuehr, Indoleamine dioxygenase and tryptophan dioxygenase activities are regulated through GAPDH- and Hsp90-dependent control of their heme levels. Free Radic Biol Med, 2022. 180: p. 179-190.

3. Leung, G.C., et al., Unravelling the mechanisms controlling heme supply and demand. Proc Natl Acad Sci U S A, 2021. 118(22).

4. Kwon, H., et al., XFEL Crystal Structures of Peroxidase Compound II. Angew Chem Int Ed Engl, 2021. 60(26): p. 14578-14585.

5. Tourigny, D.S., et al., Expression, purification, crystallization and preliminary X-ray analysis of wild-type and of an active-site mutant of glyceraldehyde-3-phosphate dehydrogenase from Campylobacter jejuni. Acta Crystallogr Sect F Struct Biol Cryst Commun, 2011. 67(Pt 1): p. 72-5.

6. Yan, J.J., et al., Resonant inelastic X-ray scattering determination of the electronic structure of oxyhemoglobin and its model complex. Proc Natl Acad Sci U S A, 2019. 116(8): p. 2854-2859.

7. Baker, M.L., et al., K- and L-edge X-ray Absorption Spectroscopy (XAS) and Resonant Inelastic X-ray Scattering (RIXS) Determination of Differential Orbital Covalency (DOC) of Transition Metal Sites. Coord Chem Rev, 2017. 345: p. 182-208.

8. Wilson, S.A., et al., X-ray absorption spectroscopic investigation of the electronic structure differences in solution and crystalline oxyhemoglobin. Proc Natl Acad Sci U S A, 2013. 110(41): p. 16333-8.

9. Kuhl, T., et al., Analysis of Fe(III) heme binding to cysteine-containing heme-regulatory motifs in proteins. ACS Chem Biol, 2013. 8(8): p. 1785-93.

10. Freeman, S.L., et al., Heme binding to human CLOCK affects interactions with the E-box. Proc Natl Acad Sci U S A, 2019. 116(40): p. 19911-19916.

11. Shimizu, T., et al., Heme: emergent roles of heme in signal transduction, functional regulation and as catalytic centres. Chem Soc Rev, 2019. 48(24): p. 5624-5657.

Project 2: Structural investigation of the intrinsically disordered regions of the RNA binding protein Sam68: implication for RNA binding and phosphorylation

Intrinsically disordered regions (IDRs) or protein play crucial roles in almost all cellular functions. Still, the molecular mechanisms that govern their functions remains largely unknown. In recent years, classical structural and biophysical techniques (NMR, FRET, SAXS, ...) have been combined with molecular dynamics simulations to generate structural ensembles and derive the mechanisms of their functions. Sam68 is a typical RNA binding protein that contains a classical folded RNA binding domain flanked by N-terminal and a C-terminal IDRs. While these IDRs have been shown to be crucial for the function of Sam68 and are targets of multiple post-translational modifications, the molecular mechanisms of their contribution remains unknown. Our published (Malki et al, NAR, 2022) and preliminary data clearly show that the Nter and Cter IDRs of Sam68 have the ability to bind RNA specifically and that phosphorylation of a single threonine residue inhibits their RNA binding ability and consequently the cellular functions on the protein.

This raises three important questions:

1- How does an unstructured protein region bind specifically an unstructured RNA? What are the molecular basis for the specificity?

2- How does phosphorylation of a single-amino acid have such an impact on the RNA binding properties of the protein?

3- How does full-length Sam68 recognize specifically its RNA targets

We will answer these questions by combining the team expertise in structural and biophysical methods (NMR, FCS, FRET, SAXS) with molecular dynamics to decipher the structural properties of these regions free, in complex with RNA and following phosphorylation.

 Project leadership team: Cyril Dominguez (University of Leicester), Andrew Hudson (University of Leicester), Marie Skepo (Lund University)

Location: Leicester, UK

Organisation: University of Leicester, The School of Chemistry

Links

AMBER call in EURAXESS main call (starting point for application)

Guide for applicants

Andrew Hudson's Profile on the University of Leicester website

The School of Chemistry, University of Leicester

Info about employment at the University of Leicester