title: Quantitative mass spectrometry analysis reveals similar substrate consensus motif for human Mps1 kinase and Plk1.
abstract: BACKGROUND
  Members of the Mps1 kinase family play an essential and evolutionarily conserved role in the spindle assembly checkpoint (SAC), a surveillance mechanism that ensures accurate chromosome segregation during mitosis. Human Mps1 (hMps1) is highly phosphorylated during mitosis and many phosphorylation sites have been identified. However, the upstream kinases responsible for these phosphorylations are not presently known.
  
  
  RESULTS
  Here, we identify 29 in vivo phosphorylation sites in hMps1. While in vivo analyses indicate that Aurora B and hMps1 activity are required for mitotic hyper-phosphorylation of hMps1, in vitro kinase assays show that Cdk1, MAPK, Plk1 and hMps1 itself can directly phosphorylate hMps1. Although Aurora B poorly phosphorylates hMps1 in vitro, it positively regulates the localization of Mps1 to kinetochores in vivo. Most importantly, quantitative mass spectrometry analysis demonstrates that at least 12 sites within hMps1 can be attributed to autophosphorylation. Remarkably, these hMps1 autophosphorylation sites closely resemble the consensus motif of Plk1, demonstrating that these two mitotic kinases share a similar substrate consensus.
  
  
  CONCLUSIONS
  hMps1 kinase is regulated by Aurora B kinase and its autophosphorylation. Analysis on hMps1 autophosphorylation sites demonstrates that hMps1 has a substrate preference similar to Plk1 kinase.
authors.affiliation: Department of Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany. douzhen@ustc.edu.cn
authors.forename: Zhen
authors.initials: Z
authors.lastname: Dou
authors.forename: Conrad
authors.initials: C
authors.lastname: von Schubert
authors.forename: Roman
authors.initials: R
authors.lastname: Körner
authors.forename: Anna
authors.initials: A
authors.lastname: Santamaria
authors.forename: Sabine
authors.initials: S
authors.lastname: Elowe
authors.forename: Erich A
authors.initials: EA
authors.lastname: Nigg
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D013379:Substrate Specificity; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D000097869:Polo-Like Kinase 1; C075840:TTK protein, human