His-tagged human Mps1^Cat encoding amino acids 510-857 is generated. For kinase assays, 500 ng is added to buffer (25 mM Tris-HCl, pH 7.4, 100 mM NaCl, 50 μg/mL BSA, 0.1 mM EGTA, 0.1% β-mercaptoethanol, 10 mM MgCl₂, and 0.5 μg/mL myelin basic protein), AZ3146, and 100 μM γ-[³²P]ATP (2 μCi/assay). Reactions are incubated at 30°C for 20 min, spotted onto P81 paper, washed in 0.5% phosphoric acid, and immersed in acetone. Phosphate incorporation is determined by scintillation counting. For immunoprecipitation kinase assays, HeLa cells are treated with nocodazole for 14 h, mitotic cells isolated, washed in PBS, and lysed for 30 min in 50 mM Tris-HCl, pH 7.4, 100 mM NaCl, 0.5% NP-40, 5 mM EDTA, 5 mM EGTA, 40 mM β-glycerophosphate, 0.2 mM PMSF, 1 mM DTT, 1 mM sodium orthovanadate, 20 mM sodium fluoride, 1 μM okadaic acid, and complete EDTA-free protease inhibitor cocktail. Full-length Mps1 is immunoprecipitated. Purified complexes are washed with lysis buffer containing 100 mM NaCl and assayed as described for the recombinant protein. To quantify ³²P incorporation, reactions are stopped with SDS sample buffer and separated by SDS-PAGE followed by phosphorimaging. The plate is analyzed using a phosphorimager using AIDA software. To assess the specificity of AZ3146, a single-point screen is carried using kinase profiling service. 50 kinases are selected and assayed with 1 μM AZ3146^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

The TTK inhibitor AZ3146 is disolved in DMSO at a concentration in 100 mM and diluted into 100 μM, 10 μM, 1 μM and 0.1 μM sequentially with DMEM containing 10% FBS before use. In vitrocytotoxicity assays are performed. HCC cells are plated into 96-well plates at the density of 3×10³ per well. AZ3146 is added in the indicated concentrations the next day. The inhibitor treated cells are cultured and tested at a 24-hour intervals for 3-4 days using CCK-8^[2].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Hewitt L, et al. Sustained Mps1 activity is required in mitosis to recruit O-Mad2 to the Mad1-C-Mad2 core complex. J Cell Biol. 2010 Jul 12;190(1):25-34.  [Content Brief]

  [2]. Liu X, et al. TTK activates Akt and promotes proliferation and migration of hepatocellular carcinoma cells. Oncotarget. 2015 Oct 27;6(33):34309-20.  [Content Brief]

  [3]. Gurden MD, et al. Naturally Occurring Mutations in the MPS1 Gene Predispose Cells to Kinase Inhibitor Drug Resistance. Cancer Res. 2015 Aug 15;75(16):3340-54.  [Content Brief]