Michael Wakelam

Michael Wakelam 1955 - 2020: read the Institute's announcement on hearing about the death of Michael on 31st March.

Research Summary

We aim to understand the essential physiological functions of lipids. Lipids are highly dynamic structures with structural, metabolic and signalling roles. To fully understand the roles that lipids have in cell function during ageing we need the ability to determine their individual changes.

The cellular lipidome is extremely complex, with distinct classes of lipids each containing many molecular species that can differ both in the length of each acyl chain present and in the number and position of double bonds.

In our lab we have pioneered the use of high-sensitivity liquid chromatography-mass spectrometry (LC-MS) technology to rapidly and comprehensively measure the levels of lipids in a wide range of cell types, tissues and tumours. The lipidome of a cell typically comprises of ~ 1500 distinct lipid species measurable with current LC-MS technology. However, this number is most likely an underestimate since there are theoretically closer to 10 000 distinct lipid species in the lipidome.

The principal aim of our laboratory is to better understand how the distinct lipid species of a cell’s lipidome function during the healthy ageing of the whole animal.

​To achieve this we use a multidisciplinary approach combining LC-MS analysis, protein biochemistry, cell biology and genetic manipulation of model organisms. This allows us to identify the cellular signalling pathways and processes that individual lipid species regulate, and to investigate how the enzymes that determine the composition of the lipidome are regulated in response to changes in the environment.

Latest Publications

Non-canonical autophagy drives alternative ATG8 conjugation to phosphatidylserine.
Durgan J, Lystad AH, Sloan K, Carlsson SR, Wilson MI, Marcassa E, Ulferts R, Webster J, Lopez-Clavijo AF, Wakelam MJ, Beale R, Simonsen A, Oxley D, Florey O

Autophagy is a fundamental catabolic process that uses a unique post-translational modification, the conjugation of ATG8 protein to phosphatidylethanolamine (PE). ATG8 lipidation also occurs during non-canonical autophagy, a parallel pathway involving conjugation of ATG8 to single membranes (CASM) at endolysosomal compartments, with key functions in immunity, vision, and neurobiology. It is widely assumed that CASM involves the same conjugation of ATG8 to PE, but this has not been formally tested. Here, we discover that all ATG8s can also undergo alternative lipidation to phosphatidylserine (PS) during CASM, induced pharmacologically, by LC3-associated phagocytosis or influenza A virus infection, in mammalian cells. Importantly, ATG8-PS and ATG8-PE adducts are differentially delipidated by the ATG4 family and bear different cellular dynamics, indicating significant molecular distinctions. These results provide important insights into autophagy signaling, revealing an alternative form of the hallmark ATG8 lipidation event. Furthermore, ATG8-PS provides a specific "molecular signature" for the non-canonical autophagy pathway.

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Molecular cell, 1, 1, 16 Apr 2021

PMID: 33909989

BioPAN: a web-based tool to explore mammalian lipidome metabolic pathways on LIPID MAPS.
Gaud C, C Sousa B, Nguyen A, Fedorova M, Ni Z, O Donnell VB, Wakelam MJO, Andrews S, Lopez-Clavijo AF

Lipidomics increasingly describes the quantitation using mass spectrometry of all lipids present in a biological sample.  As the power of lipidomics protocols increase, thousands of lipid molecular species from multiple categories can now be profiled in a single experiment.  Observed changes due to biological differences often encompass large numbers of structurally-related lipids, with these being regulated by enzymes from well-known metabolic pathways.  As lipidomics datasets increase in complexity, the interpretation of their results becomes more challenging.  BioPAN addresses this by enabling the researcher to visualise quantitative lipidomics data in the context of known biosynthetic pathways.  BioPAN provides a list of genes, which could be involved in the activation or suppression of enzymes catalysing lipid metabolism in mammalian tissues.

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F1000Research, 10, 1, 2021

PMID: 33564392

Potential Role of Oral Rinses Targeting the Viral Lipid Envelope in SARS-CoV-2 Infection.
O'Donnell VB, Thomas D, Stanton R, Maillard JY, Murphy RC, Jones SA, Humphreys I, Wakelam MJO, Fegan C, Wise MP, Bosch A, Sattar SA

Emerging studies increasingly demonstrate the importance of the throat and salivary glands as sites of virus replication and transmission in early COVID-19 disease. SARS-CoV-2 is an enveloped virus, characterized by an outer lipid membrane derived from the host cell from which it buds. While it is highly sensitive to agents that disrupt lipid biomembranes, there has been no discussion about the potential role of oral rinsing in preventing transmission. Here, we review known mechanisms of viral lipid membrane disruption by widely available dental mouthwash components that include ethanol, chlorhexidine, cetylpyridinium chloride, hydrogen peroxide, and povidone-iodine. We also assess existing formulations for their potential ability to disrupt the SARS-CoV-2 lipid envelope, based on their concentrations of these agents, and conclude that several deserve clinical evaluation. We highlight that already published research on other enveloped viruses, including coronaviruses, directly supports the idea that oral rinsing should be considered as a potential way to reduce transmission of SARS-CoV-2. Research to test this could include evaluating existing or specifically tailored new formulations in well-designed viral inactivation assays, then in clinical trials. Population-based interventions could be undertaken with available mouthwashes, with active monitoring of outcome to determine efficacy. This is an under-researched area of major clinical need.

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Function (Oxford, England), 1, 1, 2020

PMID: 33215159