Life Sciences Research for Lifelong Health

Jonathan Clark

Jonathan studied Biological Chemistry at the University of Leicester and then obtained a PhD in new synthetic methods towards the synthesis of Taxol. After a postdoctoral position in the Pharmaceutical Science Department at the University of Nottingham, he moved to Cambridge to work in the local biotechnology industry for the next 11 years. He then took up a position with Babraham Bioscience Technologies to provide chemical services to the local biotechnology industry and to help commercialise and develop science originating from the Babraham Institute. He has now taken up a position within the Institute to provide biological chemistry support to the Institute. His group carry out chemical research focused on Institute science and ageing.

Latest Publications

PI3Kδ hyper-activation promotes development of B cells that exacerbate Streptococcus pneumoniae infection in an antibody-independent manner.
Stark AK, Chandra A, Chakraborty K, Alam R, Carbonaro V, Clark J, Sriskantharajah S, Bradley G, Richter AG, Banham-Hall E, Clatworthy MR, Nejentsev S, Hamblin JN, Hessel EM, Condliffe AM, Okkenhaug K

Streptococcus pneumoniae is a major cause of pneumonia and a leading cause of death world-wide. Antibody-mediated immune responses can confer protection against repeated exposure to S. pneumoniae, yet vaccines offer only partial protection. Patients with Activated PI3Kδ Syndrome (APDS) are highly susceptible to S. pneumoniae. We generated a conditional knock-in mouse model of this disease and identify a CD19B220 B cell subset that is induced by PI3Kδ signaling, resides in the lungs, and is correlated with increased susceptibility to S. pneumoniae during early phases of infection via an antibody-independent mechanism. We show that an inhaled PI3Kδ inhibitor improves survival rates following S. pneumoniae infection in wild-type mice and in mice with activated PI3Kδ. These results suggest that a subset of B cells in the lung can promote the severity of S. pneumoniae infection, representing a potential therapeutic target.

+ View Abstract

Nature communications, 9, 2041-1723, 3174, 2018

PMID: 30093657

Genome-Scale Oscillations in DNA Methylation during Exit from Pluripotency.
Rulands S, Lee HJ, Clark SJ, Angermueller C, Smallwood SA, Krueger F, Mohammed H, Dean W, Nichols J, Rugg-Gunn P, Kelsey G, Stegle O, Simons BD, Reik W

Pluripotency is accompanied by the erasure of parental epigenetic memory, with naïve pluripotent cells exhibiting global DNA hypomethylation both in vitro and in vivo. Exit from pluripotency and priming for differentiation into somatic lineages is associated with genome-wide de novo DNA methylation. We show that during this phase, co-expression of enzymes required for DNA methylation turnover, DNMT3s and TETs, promotes cell-to-cell variability in this epigenetic mark. Using a combination of single-cell sequencing and quantitative biophysical modeling, we show that this variability is associated with coherent, genome-scale oscillations in DNA methylation with an amplitude dependent on CpG density. Analysis of parallel single-cell transcriptional and epigenetic profiling provides evidence for oscillatory dynamics both in vitro and in vivo. These observations provide insights into the emergence of epigenetic heterogeneity during early embryo development, indicating that dynamic changes in DNA methylation might influence early cell fate decisions.

+ View Abstract

Cell systems, , 2405-4712, , 2018

PMID: 30031774

Flotillin proteins recruit sphingosine to membranes and maintain cellular sphingosine-1-phosphate levels.
Riento K, Zhang Q, Clark J, Begum F, Stephens E, Wakelam MJ, Nichols BJ

Sphingosine-1-phosphate (S1P) is an important lipid signalling molecule. S1P is produced via intracellular phosphorylation of sphingosine (Sph). As a lipid with a single fatty alkyl chain, Sph may diffuse rapidly between cellular membranes and through the aqueous phase. Here, we show that the absence of microdomains generated by multimeric assemblies of flotillin proteins results in reduced S1P levels. Cellular phenotypes of flotillin knockout mice, including changes in histone acetylation and expression of Isg15, are recapitulated when S1P synthesis is perturbed. Flotillins bind to Sph in vitro and increase recruitment of Sph to membranes in cells. Ectopic re-localisation of flotillins within the cell causes concomitant redistribution of Sph. The data suggest that flotillins may directly or indirectly regulate cellular sphingolipid distribution and signalling.

+ View Abstract

PloS one, 13, 1932-6203, e0197401, 2018

PMID: 29787576

01223 496075

Email Jonathan
View Profile

Keywords

 

Facility Members

Latest Publications

Genome-Scale Oscillations in DNA Methylation during Exit from Pluripotency.

Rulands S, Lee HJ, Clark SJ

Cell systems
2405-4712: (2018)

PMID: 30031774

Microbiota derived short chain fatty acids promote histone crotonylation in the colon through histone deacetylases.

Fellows R, Denizot J, Stellato C

Nature communications
9 2041-1723:105 (2018)

PMID: 29317660

PTEN Regulates PI(3,4)P2 Signaling Downstream of Class I PI3K.

Malek M, Kielkowska A, Chessa T

Molecular cell
1097-4164: (2017)

PMID: 29056325

Insulin resistance uncoupled from dyslipidemia due to C-terminal PIK3R1 mutations.

Huang-Doran I, Tomlinson P, Payne F

JCI insight
1 :e88766 (2016)

PMID: 27766312

Dynamics of mTORC1 activation in response to amino acids.

Manifava M, Smith M, Rotondo S

eLife
5 2050-084X: (2016)

PMID: 27725083

Tumor cells with KRAS or BRAF mutations or ERK5/MAPK7 amplification are not addicted to ERK5 activity for cell proliferation.

Lochhead PA, Clark J, Wang LZ

Cell cycle (Georgetown, Tex.)
15 1551-4005:506-18 (2016)

PMID: 26959608

The inositol-3-phosphate synthase biosynthetic enzyme has distinct catalytic and metabolic roles.

Frej AD, Clark J, Roy CL

Molecular and cellular biology
1098-5549: (2016)

PMID: 26951199

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition).

Klionsky DJ, Abdelmohsen K, Abe A

Autophagy
12 1554-8635:1-222 (2016)

PMID: 26799652

Investigating the effect of arachidonate supplementation on the phosphoinositide content of MCF10a breast epithelial cells.

Anderson KE, Juvin V, Clark J

Advances in biological regulation
2212-4934: (2015)

PMID: 26639089