Microtubule Dynamics

We are currently investigating how the XMAP functions as a polymerase. We are defining the relative contribution of the different TOG domains to tubulin binding and test the hypothesis that XMAP indeed functions by increasing the rate at which single tubulin molecules associate with microtubule ends.

Andrei Pozniakovsky
Simone Reber
Per Widlund

Want to learn more about microtubule dynamics?
Watch the iBio Seminar: Building a Polymer: Microtubule Dynamics.




Associated Publications

    • Reber SB, Baumgart J, Widlund PO, Pozniakovsky A, Howard J, Hyman AA, Jülicher F. XMAP215 activity sets spindle length by controlling the total mass of spindle microtubules. Nat Cell Biol. 2013 Aug 25. [PDF][PubMed]
    • Widlund PO, Stear JH, Pozniakovsky A, Zanic M, Reber S, Brouhard GJ, Hyman AA, Howard J. Proc Natl Acad Sci USA 108: 2741-2746 (2011). [PubMed]
      The maximal growth rate of microtubules in the presence of XMAP215 is dependent on the combined affinity of TOG domains for tubulin and affinity of a separate lattice binding domain that targets the TOGs themselves to the microtubule lattice.
    • Brouhard GJ, Stear JH, Noetzel TL, Al-Bassam J, Kinoshita K, Harrison SC, Howard J, Hyman AA. XMAP215 Is a Processive Microtubule Polymerase. Cell 132 (1): 79-88 (2008). [PDF]
      XMAP215 can promote addition or removal of individual tubulin subunits from stabilized seeds in a processive manner, suggesting that it acts as a catalyst that does not require input of energy for its activity.
    • Al-Bassam J, Larsen NA, Hyman AA, Harrison SC. Crystal Structure of a TOG Domain: Conserved Features of XMAP215/Dis1-Family TOG Domains and Implications for Tubulin Binding. Structure 15: 355-362 (2007). [PDF]
      The first structure of a TOG domain shows a conserved binding surface that, when mutated, prevents the ability to bind tubulin.
    • Al-Bassam J, van Breugel M, Harrison SC, Hyman A. Stu2p binds tubulin and undergoes an open-to-closed conformational change. J Cell Biol 172: 1009-1022 (2006). [PubMed]
      The yeast XMAP215 homologue, Stu2, binds tubulin via evolutionarily conserved N-terminal TOG domains.
    • Kinoshita K, Arnal I, Desai A, Drechsel DN, Hyman AA. Reconstitution of physiological microtubule dynamics using purified components. Science 294: 1340-1343 (2001). [PubMed]
      The dynamics of microtubules in cells can be replicated in vitro by using only two factors that regulate microtubule dynamics: XMAP215 and XKCM1.
    • Tournebize R, Popov A, Kinoshita K, Ashford AJ, Rybina S, Pozniakovsky A, Mayer TU, Walczak CE, Karsenti E, Hyman AA. Control of microtubule dynamics by the antagonistic activities of XMAP215 and XKCM1 in Xenopus egg extracts. Nat Cell Biol 2: 13-19 (2000). [PubMed]
      XMAP215 is a major regulator of microtubule growth in Xenopus laevis and is antagonized by XKCM1 (MCAK).