Publication Date:
2022-05-25
Description:
© 2009 Komarova et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0. The definitive version was published in Journal of Cell Biology 184 (2009): 691-706, doi:10.1083/jcb.200807179.
Description:
End binding proteins (EBs) are highly conserved core components of microtubule plus-end tracking protein networks. Here we investigated the roles of the three mammalian EBs in controlling microtubule dynamics and analyzed the domains involved. Protein depletion and rescue experiments showed that EB1 and EB3, but not EB2, promote persistent microtubule growth by suppressing catastrophes. Furthermore, we demonstrated in vitro and in cells that the EB plus-end tracking behavior depends on the calponin homology domain but does not require dimer formation. In contrast, dimerization is necessary for the EB anti-catastrophe activity in cells; this explains why the EB1 dimerization domain, which disrupts native EB dimers, exhibits a dominant-negative effect. When microtubule dynamics is reconstituted with purified tubulin, EBs promote rather than inhibit catastrophes, suggesting that in cells EBs prevent catastrophes by counteracting other microtubule regulators. This probably occurs through their action on microtubule ends, because catastrophe suppression does not require the EB domains needed for binding to known EB partners.
Description:
This work was supported by the Netherlands Organization for Scientifi
c Research grants to A.A., by Funda ç ã o para a Ci ê ncia e a Tecnologia
fellowship to S.M. Gouveia, by a FEBS fellowship to R.M. Buey, by the National
Institutes of Health grant GM25062 to G.G. Borisy and by the Swiss
National Science Foundation through grant 3100A0-109423 and by the
National Center of Competence in Research Structural Biology program to
M.O. Steinmetz.
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
