Research project: Physiological function of the GTG/GPHRs, a highly conserved family of eukaryotic membrane proteins

The G protein-coupled receptor (GPCR)-type G proteins/Golgi pH regulators (GTGs/GPHRs) are a novel set of membrane proteins that are highly conserved in eukaryotes. So far, there have been two proposals for the role of the GTG/GPHRs: acting at the plasma membrane as a receptor for the hormone abscisic acid in Arabidopsis; or in contrast, localised at the Golgi functioning as an anion channel to regulate Golgi pH in animal cells. The project aim is therefore to determine whether there is a conserved role for these proteins. Here, the function of the GTG/GPHR family is explored in the plant and animal models, Arabidopsis thaliana and Caenorhabditis elegans respectively.  In both of these organisms there are two GTG/GPHR genes present in the genome. We showed previously that Arabidopsis gtg1gtg2 double mutants have defects in fertility, hypocotyl and root growth (Jaffe et al., 2012 The Plant Cell, 24, 3649-3668).  In this project we are  investigating the effect of knocking out the GTG/GPHR genes in C.elegans and determining their cellular localisation.  We have also used site-directed mutagenesis to verify the importance of protein domains conserved between plant and animals GTGs. 

Funding: The Gerald Kerkut Trust
Funding duration: October 2010 - September 2014

PI lead on project and contact : Dr. Lorraine E. Williams (lew@soton.ac.uk).