Introduction RhoG GTPase is a of the RAC family of RHO GTPases. It undergoes translocation from an inert cytosolic form to an activated membrane bound state after prenylation and agonist activation. It then binds to actin nucleating effectors such as diaphanous-related formin effector protein (DIAPH1) to regulate actin polymerisation (2).

Aims and methods To investigate the mechanism of RHOG protein activation during pregnancy, freshly harvested myometrial strips were solubilised into membrane and cytosolic extracts and equal aliquots were immunoblotted with RHOG and tubulin antibodies. RHOG and DIAPH1 protein expression was measured in whole tissue homogenates from non-pregnant, pregnant not in labour and spontaneous labour groups.

Results An additional prenylated RHOG fraction was noted in the pregnant groups analysed. This was absent from non-pregnant group and immunising peptide controls. The membrane bound RHOG fraction was elevated in pregnant relative to the non-pregnant groups (p<0.05). DIAPH1 expression was elevated in the spontaneous labour group (p<0.05). These findings demonstrate an increase in RHOG activity in pregnant myometrium. Further research is required to determine its function in the pregnant uterus.