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Adherens junction remodelling during mitotic rounding of pseudostratified epithelial cells
Author(s) -
AguilarAragon Mario,
Bonello Teresa T,
Bell Graham P,
Fletcher Georgina C,
Thompson Barry J
Publication year - 2020
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.15252/embr.201949700
Subject(s) - adherens junction , microbiology and biotechnology , mitosis , biology , chemistry , cadherin , genetics , cell
Abstract Epithelial cells undergo cortical rounding at the onset of mitosis to enable spindle orientation in the plane of the epithelium. In cuboidal epithelia in culture, the adherens junction protein E‐cadherin recruits Pins/ LGN / GPSM 2 and Mud/Nu MA to orient the mitotic spindle. In the pseudostratified columnar epithelial cells of Drosophila , septate junctions recruit Mud/Nu MA to orient the spindle, while Pins/ LGN / GPSM 2 is surprisingly dispensable. We show that these pseudostratified epithelial cells downregulate E‐cadherin as they round up for mitosis. Preventing cortical rounding by inhibiting Rho‐kinase‐mediated actomyosin contractility blocks downregulation of E‐cadherin during mitosis. Mitotic activation of Rho‐kinase depends on the Rho GEF ECT 2/Pebble and its binding partners Rac GAP 1/MgcRac GAP / CYK 4/Tum and MKLP 1/ KIF 23/ ZEN 4/Pav. Cell cycle control of these Rho activators is mediated by the Aurora A and B kinases, which act redundantly during mitotic rounding. Thus, in Drosophila pseudostratified epithelia, disruption of adherens junctions during mitosis necessitates planar spindle orientation by septate junctions to maintain epithelial integrity.