Co-workers: Dr.Izabela Bombik, Fusheng Chang, Li-Yao Huang, Dr.Seiji Ura, Eleanor Warren, Dr.Huajiang Xiong
My lab studies the importance of post-translational modification of proteins in regulating cell behaviour using two experimental systems: the social amoeba Dictyostelium and human platelets.
We exploit molecular genetic, biochemical and cell biology techniques to study changes in cell behaviour in the haploid eukaryote Dictyostelium discoideum. Dictyostelium grows as single amoebae. Starvation triggers a developmental life cycle in which amoebae aggregate to form a multicellular structure containing a head of spores supported by a stalk of dead cells. This organism is therefore ideal to study signaling pathways involved in regulation of differentiation. Modifications of histones associated with developmental genes are implicated in control of expression and we are determining their importance in controlling cell fate. Histone variants are encoded by single copy genes in Dictyostelium, facilitating gene replacement studies to introduce mutations at modification sites in endogenous histones to determine the consequences for cell function. Histone modification also plays a major part in DNA damage response. Many human DNA damage response pathways are highly conserved in Dictyostelium, for example
ADPribosylation of histone proteins at sites of damage, and we are using gene replacement technology to determine the functional importance (collaboration with Nick Lakin).
We collaborate with industrial partners to use Dictyostelium as a non-animal model to predict developmental toxicity of environmental compounds, as well as pharmaceutical agents, exploiting genetics to identify mode of action.
We are investigating signaling pathways regulating activation of human platelets (collaboration with Steve Watson, Birmingham University) with implications for understanding of bleeding disorders and thrombotic disease caused by inappropriate platelet function. We are particular focusing on proteomic approaches to understand the role of the post-translational addition of ubiquitin to signaling proteins in modulation of platelet responses as a potential therapeutic target.
This work is made possible by funding from NC3Rs, British Heart Foundation, BBSRC and MRC.
- Plank, M., Fischer, R., Geoghegan, V., Charles, P.D., Konietzny, R., Acuto, O., Pears, C., Schofield, C.J., Kessler, B.M. (2015) Expanding the yeast protein arginine methylome. Proteomics 15, 3232-43
- Pears, C. and Lakin, N. (2014) Emerging models for DNA repair: Dictyostelium discoideum as a model for non homologous end-joining. DNA Repair 17, 121-131
- Unsworth, A.J., Finney B.A, Navarro-Nunez, L., Severin S., Watson S.P and Pears C.J. (2012) PKCε and PKCθ double-deficient mice have a bleeding diathesis. J. Thromb. Haemost. 10, 1887-1894
- Hsu, DW., Chubb, J., Muramoto, T., Pears, C. and Mahadevan, L. (2012) Dynamic acetylation of Lysine-4 trimethylated Histone H3 and H3 variant biology in a simple multicellular eukaryote. Nucl. Acids Res. 40, 7247-56
- Couto, C., Wang, H-Y., Green, J., Kiely R., Siddaway, R., Borer, C., Pears, C. and Lakin N (2011) PARP regulates non-homologous end-joining through retention of Ku at double strand breaks. J. Cell Biol. 194, 367-375
- Hudson, J., Hsu, D., Guo, K., Zhukovskaya, N., Liu, P., Williams, J., Pears, C. and Lakin, N. (2005) DNA-PKcs dependent signaling of DNA damage in Dictyostelium discoideum. Curr. Biol. 15, 1880-1885
Figure 1: Life cycle of Dictyostelium discoideum
Figure 2: Mature fruiting bodies stained for expression of b-galactosidase driven from a promoter preferentially expressed in the precursors of either stalk (A) or spore (B) cells
Figure 3: Development of parental Dictyostelium cells (i) in comparison with cells in which the gene encoding the kinase Cdk8 has been disrupted (ii)
Figure 4: Time course of human platelet spreading on surface of fibrinogen
Postdoc and Graduate Student Positions: Enquiries with CV welcome