Self-organization of an acentrosomal microtubule network at the basal cortex of polarized epithelial cells.
Mechanisms underlying the organization of centrosome-derived microtubule arrays are well understood, but less is known about how acentrosomal microtubule networks are formed. The basal cortex of polarized epithelial cells contains a microtubule network of mixed polarity. We examined how this network is organized by imaging microtubule dynamics in acentrosomal basal cytoplasts derived from these cells. We show that the steady-state microtubule network appears to form by a combination of microtubule-microtubule and microtubule-cortex interactions, both of which increase microtubule stability. We used computational modeling to determine whether these microtubule parameters are sufficient to generate a steady-state acentrosomal microtubule network. Microtubules undergoing dynamic instability without any stabilization points continuously remodel their organization without reaching a steady-state network. However, the addition of increased microtubule stabilization at microtubule-microtubule and microtubule-cortex interactions results in the rapid assembly of a steady-state microtubule network in silico that is remarkably similar to networks formed in situ. These results define minimal parameters for the self-organization of an acentrosomal microtubule network.
Reilein
Amy
A
Department of Biological Sciences, Beckman Center for Molecular and Genetic Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
Yamada
Soichiro
S
Nelson
W James
WJ
D000818:Animals; D002460:Cell Line; D016764:Cell Polarity; D018385:Centrosome / Q000502:physiology* / Q000648:ultrastructure; D003198:Computer Simulation; D004285:Dogs; D004705:Endocytosis / Q000502:physiology; D004847:Epithelial Cells / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008870:Microtubules / Q000502:physiology* / Q000648:ultrastructure; D008954:Models, Biological; D022142:Secretory Vesicles / Q000502:physiology / Q000648:ultrastructure