Tales of RAM and MOR: NDR kinase signaling in fungal morphogenesis

NDR kinases are crucial for growth, differentiation, and pathogenicity in all analyzed fungal species. They require association with MOB co-activators and several scaffolding proteins for their function. Phosphorylation of two conserved residues in the activation segment and the hydrophobic motif controls the transition between an enzymatic inactive, basal active, and fully active state of the NDR kinase. Although cellular functions of NDR kinases are only beginning to emerge, regulation of small G-proteins of the Rho and Rab families and combinatorial transcriptional and translational regulation of gene expression are conserved signaling patterns among fungal and higher eukaryotic NDR kinase pathways.