Function
Regulates asymmetric cell division (ACD), especially in stomatal-lineage cells, probably by modulating accumulation and subcellular polarization of POLAR and SPCH (PubMed:30429609, PubMed:25843888). Mediates an attenuation of MAPK signaling upon polarization of POLAR and ASK7/BIN2 in stomatal lineage ground cells (SLGCs) undergoing ACD, and relieves BIN2 inhibition of SPCH in the nucleus (PubMed:30429609, PubMed:25843888). When phosphorylated, functions as a scaffold and recruits the MAPKKK YODA, MPK3 and MPK6 to spatially reorganize the MAPK signaling pathway at the cortex of cells undergoing ACD (PubMed:25843888). Cortical polarization leads to elevated nuclear MPK6 signaling and lowered SPCH abundance in one of the two daughter cells, thus differentiating the two daughter cells after ACD (PubMed:27746029).