Simeon Draganov

A mass spectometry and chemical biology approach to dissecting the molecular basis of Tissue Factor regulation via post-translational modifications of RNA-binding proteins

Simeon Draganov - 1st year PhD


Tissue Factor (TF, coagulation factor III) is a cellular activator of coagulation that is constitutively expressed by many parenchymal cells and is necessary for haemostasis. However, TF expression is selectively induced during inflammation in monocytes/macrophages and can drive thrombosis. Our recent work has demonstrated that this response largely driven by post-transcriptional regulation of TF mRNA stability and translation which is mediated by ribonucleoprotein (RNP) complexes and their post-translational modifications (PTMs), including phosphorylation and ADP-ribosylation (Iqbal et al., Blood, 2014: 124). This proposal aims to combine chemical biology tools with mass spectrometry (MS) to elucidate how these PTMs function as regulatory switch to control the dynamics of RNP complex composition and ultimately drive TF expression during inflammation. Specifically, we will create novel NAD analogues, the co-factor for ADP-ribosylation, which will offer selective enrichment pathways for ADP-ribosylated peptides that are compatible with mass spectrometry (MS) for high-throughput site identification. This core technology will be combined with our recently developed MS proteomics pull-down workflows (including phosphoproteomics) using RNA probes to provide a holistic and dynamic description of the RNP complexes and PTMs that regulate TF mRNA stability.