Abstract
We have previously identified a new centrosomal protein, centrosomal protein 4.1-associated protein (CPAP), which is associated with the γ-tubulin complex. Here, we report that CPAP carries a novel microtubule-destabilizing motif that not only inhibits microtubule nucleation from the centrosome but also depolymerizes taxol-stabilized microtubules. Deletion mapping and functional analyses have defined a 112-residue CPAP that is necessary and sufficient for microtubule destabilization. This 112-residue CPAP directly recognizes the plus end of a microtubule and inhibits microtubule nucleation from the centrosome. Biochemical and functional analyses revealed that this 112-residue CPAP also binds to tubulin dimers, resulting in the destabilization of microtubules. Using the tetracycline-controlled system (tet-off), we observed that overexpression of this 112-residue CPAP inhibits cell proliferation and induces apoptosis after G2/M arrest. The possible mechanisms of how this 112-residue motif in CPAP that inhibits microtubule nucleation from the centrosome and disassembles preformed microtubules are discussed.
Original language | English |
---|---|
Pages (from-to) | 2697-2706 |
Number of pages | 10 |
Journal | Molecular Biology of the Cell |
Volume | 15 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2004 |