We have used green fluorescent protein fusions to localise flax resistance proteins conferring resistance to flax rust.
The flax L6 and M resistance proteins, which confer resistance to flax rust (pictured), have N-terminal membrane-anchoring domains. We have used green fluorescent protein fusions to these N-terminal domains to show that L6 is localised to the cytosolic face of the Golgi apparatus and M to the cytosolic face of the tonoplast (Takemoto et al. 2012). The localisation of M is unique among the L and M families of resistance proteins with those characterised to date all having N-terminal membrane-anchoring domains similar to L6.
Why are these resistance protein membrane-anchored and why are they anchored to different membranes? We are using a combination of genetic, molecular biology and cell biology techniques to address these questions.