Structural Basis for Auto-Inhibition of the NDR1 Kinase Domain by an Atypically Long Activation Segment

Structure. 2018 Aug 7;26(8):1101-1115.e6. doi: 10.1016/j.str.2018.05.014. Epub 2018 Jul 5.


The human NDR family kinases control diverse aspects of cell growth, and are regulated through phosphorylation and association with scaffolds such as MOB1. Here, we report the crystal structure of the human NDR1 kinase domain in its non-phosphorylated state, revealing a fully resolved atypically long activation segment that blocks substrate binding and stabilizes a non-productive position of helix αC. Consistent with an auto-inhibitory function, mutations within the activation segment of NDR1 dramatically enhance in vitro kinase activity. Interestingly, NDR1 catalytic activity is further potentiated by MOB1 binding, suggesting that regulation through modulation of the activation segment and by MOB1 binding are mechanistically distinct. Lastly, deleting the auto-inhibitory activation segment of NDR1 causes a marked increase in the association with upstream Hippo pathway components and the Furry scaffold. These findings provide a point of departure for future efforts to explore the cellular functions and the mechanism of NDR1.

Keywords: FRYL; Furry-like; Hippo tumor suppressor pathway; MOB1; NDR family; X-ray crystallography; kinases; protein kinase.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / chemistry*
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Amino Acid Sequence
  • Binding Sites
  • Cell Cycle Proteins
  • Cell Line, Tumor
  • Cloning, Molecular
  • Crystallography, X-Ray
  • Epithelial Cells / cytology
  • Epithelial Cells / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Gene Expression
  • Gene Expression Regulation
  • Genetic Vectors / chemistry
  • Genetic Vectors / metabolism
  • HEK293 Cells
  • Hepatocyte Growth Factor / chemistry*
  • Hepatocyte Growth Factor / genetics
  • Hepatocyte Growth Factor / metabolism
  • Humans
  • Kinetics
  • Microtubule-Associated Proteins / chemistry*
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism
  • Models, Molecular
  • Mutation
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • Protein Serine-Threonine Kinases / chemistry*
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / chemistry*
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Serine-Threonine Kinase 3
  • Signal Transduction
  • Substrate Specificity


  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • FRY protein, human
  • MOB1A protein, human
  • Microtubule-Associated Proteins
  • Proto-Oncogene Proteins
  • Recombinant Proteins
  • macrophage stimulating protein
  • Hepatocyte Growth Factor
  • Protein Serine-Threonine Kinases
  • STK3 protein, human
  • STK38 protein, human
  • Serine-Threonine Kinase 3