Microtubule plus-end-binding proteins target the microtubule plus ends, and thus control the lengths and positions of microtubules in cells. There are three microtubule end-binding (EB) proteins that are expressed in mammalian cells, and they are highly conserved core components of the microtubule plus-end-tracking protein machinery. EB1 and EB3 (also known as MAPRE1 and MAPRE3, respectively) are known to influence microtubule dynamics, but the function of EB2 in cells remains unclear. Here (p. 4000), Mette Mogensen and colleagues investigate the role of EB2 in microtubule reorganisation and apico-basal bundle formation during epithelial differentiation. The authors report inhibition of microtubule reorganisation following small interfering RNA depletion of EB2 during the early stages of apico-basal differentiation; the downregulation of EB2 at later stages, however, promoted microtubule stability and bundle formation. EB2 knockdown in undifferentiated cells was found to induce straight, less dynamic microtubules and led to EB1 lattice binding, recruitment of the microtubule–actin crosslinking spectraplakin ACF7 and co-alignment with actin filaments; this phenotype was rescued by inhibition of formins, which are downstream effectors of Rho GTPases. Finally, to confirm these in vitro findings in vivo, the authors studied in situ inner ear and intestinal crypt epithelial tissue, finding that a low level of EB2 expression correlated directly with the presence of apico-basal microtubule bundles, which were absent where EB2 was elevated. This is the first demonstration of a role for EB2 in microtubule reorganisation during apico-basal epithelial differentiation.
IN THIS ISSUE| 01 September 2013
Key role for EB2 in microtubule reorganisation
Online Issn: 1477-9137
Print Issn: 0021-9533
© 2013. Published by The Company of Biologists Ltd
J Cell Sci (2013) 126 (17): e1706.
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Key role for EB2 in microtubule reorganisation. J Cell Sci 1 September 2013; 126 (17): e1706. doi:
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