The microtubule end-binding protein EB2 is a central regulator of microtubule reorganisation in apico-basal epithelial differentiation

Deborah Goldspink, Jonathan Gadsby, Gemma Bellett, Jennifer Keynton, Benjamin Tyrrell, Elizabeth Lund, Penny Powell, Paul Thomas, Mette Mogensen

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Microtubule end-binding (EB) proteins influence microtubule dynamic instability, a process that is essential for microtubule reorganisation during apico-basal epithelial differentiation. Here, we establish for the first time that expression of EB2, but not that of EB1, is crucial for initial microtubule reorganisation during apico-basal epithelial differentiation, and that EB2 downregulation promotes bundle formation. EB2 siRNA knockdown during early stages of apico-basal differentiation prevented microtubule reorganisation, whereas its downregulation at later stages promoted microtubule stability and bundle formation. Interestingly, although EB1 is not essential for microtubule reorganisation, its knockdown prevented apico-basal bundle formation and epithelial elongation. siRNA depletion of EB2 in undifferentiated epithelial cells induced the formation of straight, less dynamic microtubules with EB1 and ACF7 lattice association and co-alignment with actin filaments, a phenotype that could be rescued by inhibition with formin. Importantly, in situ inner ear and intestinal crypt epithelial tissue revealed direct correlations between a low level of EB2 expression and the presence of apico-basal microtubule bundles, which were absent where EB2 was elevated. EB2 is evidently important for initial microtubule reorganisation during epithelial polarisation, whereas its downregulation facilitates EB1 and ACF7 microtubule lattice association, microtubule-actin filament co-alignment and bundle formation. The spatiotemporal expression of EB2 thus dramatically influences microtubule organisation, EB1 and ACF7 deployment and epithelial differentiation.
Original languageEnglish
Pages (from-to)4000-4014
Number of pages15
JournalJournal of Cell Science
Volume126
Issue numberPt 17
DOIs
Publication statusPublished - 1 Sep 2013

Keywords

  • EB2
  • EB1
  • ACF7
  • Epithelia
  • Microtubules
  • Cochlea
  • Intestinal crypt
  • Actin filaments

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