NDR

NDR kinases, NDR1/STK38 and NDR2/STK38L, sit at the intersection of the AGC family and the Hippo pathway. Each enzyme combines an N-terminal basic regulatory region, a kinase domain, and a C-terminal hydrophobic motif; binding of MOB1A/B coactivators relieves autoinhibition and permits PDK1-dependent activation-loop phosphorylation, while upstream MST1/2 kinases further stimulate the pathway. NDR1 and NDR2 control centrosome duplication and mitotic fidelity, apoptotic signaling downstream of MST kinases, and dendritic and axonal morphogenesis in neurons. Loss of NDR function is linked to chromosomal instability and tumor predisposition in mouse models, and reduced NDR2 levels occur in human cancers. Recombinant NDR proteins, often supplied with MOB1, support Hippo-pathway reconstitution, substrate-phosphorylation, and tumor-suppressor studies.