Yeast two-hybrid interactions between <i>Arabidopsis lyrata S</i> Receptor Kinase and the ARC1 E3 ligase

Here we describe protein-protein interactions between signaling components in the conserved self-incompatibility pathway from <i>Brassica spp</i>. and <i>Arabidopsis lyrata</i>. Previously, we had demonstrated that ARC1 is necessary in <i>A. lyrata</i> for the rejection of self-pollen by the self-incompatibility pathway. The results described here demonstrate that <i>A. lyrata</i> ARC1 interacts with <i>A. lyrata S</i> Receptor Kinase (SRK₁) in the yeast 2-hybrid system. <i>A. lyrata</i> ARC1 also interacted with <i>B. napus</i> SRK₉₁₀ illustrating that interactions in this pathway are conserved across species. Finally, we discuss how the more widely occurring interactions between SRK and ARC1-related family members may be modulated <i>in vivo</i> by expression and subcellular localization patterns resulting in a particular response.