AZ3146

AZ3146的生物活性 AZ3146 is a potent and selective monopolar spindle 1 (Mps1) kinase inhibitor (IC50 = 35 nM); less potent to FAK, JNK1, JNK2, and Kit. IC50 Value: 35 nM Target: Mps1 in vitro: AZ3146 also inhibits FAK, JNK1, JNK2 and Kit. AZ3146 significantly inhibits phosphorylation of Mps1 in cells. Mitotic-specific phospho forms of aurora B and BubR1 are not affected by AZ3146. AZ3146 does not inhibit Cdk1 or aurora B in mitotic cells. HeLa cells treated with nocodazole and 2 μM AZ3146 only delay mitosis briefly and then rereplicate their genomes, indicating that AZ3146 overrides the SAC. AZ3146 also inhibits an already established SAC signal, as after release from a nocodazole block, AZ3146 dramatically accelerates mitotic exit.During an otherwise unperturbed mitosis, AZ3146 reduces the time to complete mitosis from 90 minutes in controls to 32 minutes. Strikingly, ~90% of AZ3146-treated HeLa cells undergo abnormal mitoses, although ~50% enter anaphase without aligning all of their chromosomes, and ~30% exit mitosis without undergoing obvious chromosome segregation. AZ3146 has a dramatic effect on kinetochore localization of Mad2, reducing its levels to ~15%, but its effect on Mad1 is less pronounced, with levels remaining at ~60%. When Mps1 is inhibited by AZ3146 before mitotic entry, subsequent recruitment of Mad1 and Mad2 to kinetochores is abolished. However, if Mps1 is inhibited by AZ3146 after mitotic entry, the Mad1–C-Mad2 core complex remains kinetochore bound, but O-Mad2 is not recruited to the core. in vivo: