UC San Diego

PRONE RopGEFs are a family of plant specific GEFs with roles in cell morphogenesis, polarity, and growth. Along with roles in ROP activation, RopGEFs have been found to interact with leucine-rich repeat receptor-like kinases (LRR-RLKs) in various plant species such as tomato and Arabidopsis. In maize, LRR-RLK, PAN1, and ROPs promote cell polarization during stomatal development. In this study, RopGEFs were investigated as possible linkers between PAN1 and ROP in this pathway. Five RopGEFs (RopGEF1-5) were chosen for investigation and tested for direct interaction with PAN1. An antibody was designed to characterize the RopGEFs and found to recognize multiple bands in maize protein extracts. Tissue staining with the antibody showed an accumulation of proteins around the nucleus in various cell types. When bombarded with a GFP construct containing one of the RopGEFs (RopGEF5), dot- like aggregates of varying sizes were seen along the cell periphery. RopGEF4 was found to interact with PAN1 in the yeast 2-hybrid system, supporting the possibility of RopGEF activity in the PAN1 pathway