Orientation of spindle axis and distribution of plasma membrane proteins during cell division in polarized MDCKII cells.

Abstract

Abstract. MDCKII cells differentiate into a simple columnar epithelium when grown on a permeable support; the monolayer is polarized for transport and secretion. Individual cells within the monolayer continue to divide at a low rate without disturbing the function of the epithelium as a barrier to solutes. This presents an interesting model for the study of mitosis in a differentiated epithelium which we have investigated by confocal immunofluorescence microscopy. We monitored the distribution of microtubules, centrioles, nucleus, tight junctions, and plasma membrane proteins that are specifically targeted to the apical and basolateral domains. The stable interphase microtubule cytoskeleton was rapidly disassembled at prophase onset and reassembled at cytokinesis. As the interphase microtubules disassembled at prophase, the centrioles moved from their interphase position at the apical membrane to the nucleus and acquired the ability to organize microtubule asters. Orientation of the spindle parallel to the plane of the monolayer occurred between late prophase and metaphase and persisted through cytokinesis. The cleavage furrow formed asymmetrically perpendicular to the plane of the monolayer initiating at the basolateral side and proceeding to the apical domain. The interphase microtubule network reformed after the centrioles migrated from the spindle poles to resume their interphase apical position. Tight junctions (ZO-1), which separate the apical from the basolateral domains, remained assembled throughout all phases of mitosis. E-cadherin and a 58-kD antigen maintained their basolateral plasma membrane distributions, and a 114-kD antigen remained polarized to the apical domain. These proteins were useful for monitoring the changes in shape of the mitotic cells relative to neighboring cells, especially during telophase when the cell shape changes dramatically.We discuss the changes in centriole position during the cell cycle, mechanisms of spindle orientation, and how the maintenance of polarized plasma membrane domains through mitosis may facilitate the rapid reformation of the polarized interphase cytoplasm.

Emergence of homeostatic epithelial packing and stress dissipation through divisions oriented along the long cell axis

“…S6 B and C) rather than the most elongated, as would have been expected if mitotic entry were triggered by a mechanical cue. These cells then all divided in the plane of the epithelium, as observed for monolayers growing on substrates (22) (Fig. 2A and Fig.…”

Lateral Membrane Biogenesis in Human Bronchial Epithelial Cells Requires 190-kDa Ankyrin-G

“…Polarized epithelial cells undergoing cell division create a new lateral membrane that separates the two daughter cells in the final phase of cytokinesis. For example, the lateral membrane in MDCKII cells undergoing cytokinesis is formed by the telophase stage and has a polarized distribution of E-cadherin (31). Mitotic cells thus provide a means of observing de novo biogenesis of the lateral membrane separate from secondary remodeling pathways.…”

Cytoskeletal Molecules Play a Major Role in Cancer Progression

“…They mainly participate in transport of vesicles and organelles within cells and the formation of mitotic spindles during cell division. Structural instability, microtubule assembly and disassembly, is regulated by microtubuleassociated proteins [5]. During cell division, dynamic instability of microtubules plays a major role in metaphase and anaphase by rapid assembly and disassembly respectively.…”