Short CommunicationERas protein is overexpressed and binds to the activated platelet-derived growth factor β receptor in bovine urothelial tumour cells associated with papillomavirus infection

- ERas, a member of the Ras family, is a constitutive gene of bovine urothelial cells.
- ERas forms a constitutive complex with PDGFβR in urothelial cells.
- ERas is upregulated and ERas protein is overexpressed in bovine urothelial tumours.
- ERas binds to the activated PDGFβR in papillomavirus-associated urothelial tumours.
- Phosphorylation of Akt, an ERas and PDGFβR downstream effector, is increased.

Embryonic stem cell-expressed Ras (ERas) encodes a constitutively active form of guanosine triphosphatase (GTPase) that binds to and activates phosphatidylinositol 3 kinase (PI3K), which in turn phosphorylates and activates downstream targets such as Akt. The current study evaluated ERas regulation and expression in papillomavirus-associated urothelial tumours in cattle grazing on lands rich in bracken fern. ERas was found upregulated and overexpressed by PCR, real time PCR and Western blot. Furthermore, protein overexpression was also confirmed by immunohistochemistry. ERas was found to interact physically and colocalise with the activated platelet derived growth factor β receptor (PDGFβR) by coimmunoprecipitation and laser scanning confocal investigations. Phosphorylation of Akt, a downstream effector both of ERas and PDGFβR, appeared to be increased in urothelial tumour cells. Altogether, these data indicate that ERas/PDGFβR complex could play a role in the pathogenesis of bovine papillomavirus-associated bladder neoplasia.