Fig 9. Summary and working model.

(A) Table summarises phenotypes observed in the DT40 TACC3 mutants. Cell doubling time of F543A is similar to WT, but hmC levels indicate faster proliferation, hence the n.e./+ description. (B) Model illustrates roles of different TACC3 pools during mitosis. Briefly, in prometaphase TACC3 is phosphorylated on S558 by TPX2-bound Aurora-A, and P-TACC3 enhances MT polymerase activity of ch-TOG both near centrosomes and chromatin. As kinetochore MTs become established, TACC3 recruits clathrin to these MTs, but the complex is initially unstable. Long-lived kinetochore MTs allow local activation of Aurora-A by TACC3 and phosphorylation at S558 stabilises the TACC3-clathrin complex, which in turn crosslinks these MTs.