ERG, an ETS transcription factor, is considered a master regulator of myriad vascular processes including homeostasis, angiogenesis, inflammation, vascular development and haemostasis. The pathological dysregulation of endothelial ERG has been linked to inflammatory disorders and diseases associated with abnormal vascular homeostasis. In non-EC, the aberrant ectopic expression of ERG can result in the pathogenesis of multiple cancers. ERG activity has been shown to be regulated through ERK2 dependent phosphorylation of serines 96 and 215. Little is known about the molecular mechanisms underlying the regulation of ERG’s transcriptional activity through phosphorylation. We combine in silico Molecular Dynamics (MD) and in vitro assays to characterise the molecular mechanisms underlying the phosphorylation dependent regulation of ERG’s transcriptional activity. No full-length crystal structure of ERG has yet been obtained, possibly due to a high percentage of flexible random coil regions in its structure. Thus, a model of the full-length structure of the ERGp55 isoform was generated using MD that relied on the available structural information for two conserved domains.The validity of the in silico ERGp55 MD model was confirmed by reproducing experimentally derived DNA binding characteristics. This model was then used to show that upon serine 215 and 96 phosphorylation ERGp55 structure underwent conformational changes in the C- and N- termini. To investigate whether these structural changes were functionally relevant, we carried out an in vitro Luciferase promoter reporterassay using ERGp55 phosphorylation mutants. We showed that both serine 215 and 96 phosphorylation events are required to increase ERGp55’s transactivation of a target gene promoter in HeLa cells. Ongoing in vitro studies are characterising the effect of ERGp55 phosphorylation on the interactions of ERGp55 with protein binding partners and target DNA sequences. Understanding how the dynamic regulation of ERG’s protein structure is linked to its functionality can provide knowledge on how to design therapeutics that can impair or mimic ERG activity in order to tackle diseases associated with abnormal vascular homeostasis.

Using molecular dynamics to understand the molecular mechanisms underlying the regulatory activity of the transcription factor ERG

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.