title: An unconventional interaction between Dis1/TOG and Mal3/EB1 in fission yeast promotes the fidelity of chromosome segregation.
abstract: 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, the XMAP215, ch-TOG or CKAP5 family and the end-binding 1 (EB1, also known as MAPRE1) family, play pivotal roles in regulating microtubule dynamics. Here, we study the functional interplay between fission yeast Dis1, a member of the XMAP215/TOG family, and Mal3, an EB1 protein. 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 new 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 interaction between EB1 and the XMAP215/TOG family members requires an additional binding partner, fission yeast relies on a direct interaction, indicating evolutionary plasticity of this critical interaction module.
authors.affiliation: Synthetic and Systems Biochemistry of the Microtubule Cytoskeleton Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.|Cell Regulation Laboratory, The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
authors.forename: Yuzy
authors.initials: Y
authors.lastname: Matsuo
authors.affiliation: Synthetic and Systems Biochemistry of the Microtubule Cytoskeleton Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.|Cell and Developmental Biology, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, Barcelona 08003, Spain.|Universitat Pompeu Fabra (UPF), Barcelona 08002, Spain.
authors.forename: Sebastian P
authors.initials: SP
authors.lastname: Maurer
authors.affiliation: Hiroshima Research Center for Healthy Aging (HiHA), Department of Molecular Biotechnology, Graduate School of Advanced Science of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Yukawa
authors.affiliation: Structural Biology of Chromosome Segregation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
authors.forename: Silva
authors.initials: S
authors.lastname: Zakian
authors.affiliation: Structural Biology of Chromosome Segregation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Singleton
authors.affiliation: Synthetic and Systems Biochemistry of the Microtubule Cytoskeleton Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK Thomas.Surrey@crick.ac.uk takashi-toda@hiroshima-u.ac.jp.
authors.forename: Thomas
authors.initials: T
authors.lastname: Surrey
authors.affiliation: Cell Regulation Laboratory, The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK Thomas.Surrey@crick.ac.uk takashi-toda@hiroshima-u.ac.jp.|Hiroshima Research Center for Healthy Aging (HiHA), Department of Molecular Biotechnology, Graduate School of Advanced Science of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan.
authors.forename: Takashi
authors.identifier: 0000-0001-7851-1757
authors.initials: T
authors.lastname: Toda
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D020090:Chromosome Segregation; D018360:Crystallography, X-Ray; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D008958:Models, Molecular; D011485:Protein Binding; D000072417:Protein Domains; D012568:Schizosaccharomyces / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000596:Amino Acids; C108851:Mal3 protein, S pombe; D008869:Microtubule-Associated Proteins; D029702:Schizosaccharomyces pombe Proteins; C094879:dis1 protein, S pombe
keywords: Crystallography; EB1; Microtubule polymerase; TIRF microscopy; TOG; XMAP215