5m97

Publication Abstract from PubMed

Dynamic microtubule plus ends interact with various intracellular target regions such as the cell cortex and the kinetochore. Two conserved families of microtubule plus-end tracking proteins, XMAP215/TOG and EB1, play pivotal roles in regulating microtubule dynamics. Here we study the functional interplay between fission yeast Dis1/XMAP215 and Mal3/EB1. Using an in vitro microscopy assay, we find that purified Dis1 autonomously tracks growing microtubule ends and is a bona fide microtubule polymerase. Mal3 recruits additional Dis1 to microtubule ends, explaining the synergistic enhancement of microtubule dynamicity by these proteins. A non-canonical binding motif in Dis1 mediates the interaction with Mal3. X-ray crystallography shows that this novel motif interacts in an unconventional configuration with the conserved hydrophobic cavity formed within the Mal3 C-terminal region that typically interacts with the canonical SXIP motif. Selectively perturbing the Mal3-Dis1 interaction in living cells demonstrates that it is important for accurate chromosome segregation. Whereas in some metazoans the EB1-XMAP215/TOG interaction requires an additional binding partner, fission yeast relies on a direct interaction, indicating evolutionary plasticity of this critical interaction module.

An unconventional interaction between Dis1/TOG and Mal3/EB1 promotes the fidelity of chromosome segregation.,Matsuo Y, Maurer SP, Yukawa M, Zakian S, Singleton MR, Surrey T, Toda T J Cell Sci. 2016 Nov 21. pii: jcs.197533. PMID:27872152^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.