Regulation and regulatory activities of centrosomes

The centrosome functions in the organization of the cytoskeleton, in specification of cell polarity, and in the assembly of the bipolar spindle during mitosis. These activities are largely the result of microtubule nucleation activity and the centrosome's structural influence on the form of the microtubule array that it anchors. Centrosome duplication and microtubule nucleation activity are precisely regulated during development and the cell cycle. Loss of normal centrosome regulation and function may lead to alterations in cell polarity and to chromosomal instability through mitotic defects resulting in aneuploidy. This is particularly true for many malignant tumors. Here, we review the regulation and regulatory activities of centrosomes and consider some of the questions of current interest in this area.