Transitions from Centrosomal to Non-centrosomal Microtubule Organization During Cellular Polarization.

Cellular polarization involves significant remodeling and decentralization of the nucleus-associated centrosome to focal points at the apical and basolateral surfaces which is associated with major remodeling of the microtubule system in which individual microtubules become nucleated and organized from the polarizing cell surfaces, as studied in polarizing epithelial cells (reviewed in Müsch 2004; Muroyama and Lechler 2017). These changes are associated with cellular asymmetry in preparation for cellular differentiation of previously non-committed cells. During this process, the previously nucleus-associated centrosome becomes deconstructed into specific centrosomal components which are now referred to as "non-centrosomal." At the present time we still only have limited information about this process and to understanding the mechanisms underlying the centrosome decentralization process. Gaining detailed insights is further complicated by the fact that there is considerable diversity in the molecular mechanisms of centrosome and microtubule reorganization.