Abstract
In budding yeast, the microtubule plus-end tracking proteins Bik1 (CLIP-170) and Bim1 (EB1) form a complex that interacts with partners involved in spindle positioning, including Stu2 and Kar9. Here, we show that the CAP-Gly and coiled-coil domains of Bik1 interact with the C-terminal ETF peptide of Bim1 and the C-terminal tail region of Stu2, respectively. The crystal structures of the CAP-Gly domain of Bik1 (Bik1CG) alone and in complex with an ETF peptide revealed unique, functionally relevant CAP-Gly elements, establishing Bik1CG as a specific C-terminal phenylalanine recognition domain. Unlike the mammalian CLIP-170-EB1 complex, Bik1-Bim1 forms ternary complexes with the EB1-binding motifs SxIP and LxxPTPh, which are present in diverse proteins, including Kar9. Perturbation of the Bik1-Bim1 interaction in vivo affected Bik1 localization and astral microtubule length. Our results provide insight into the role of the Bik1-Bim1 interaction for cell division, and demonstrate that the CLIP-170-EB1 module is evolutionarily flexible.
Keywords:
CAP-Gly domains; X-ray crystallography; microtubule plus-end tracking proteins; protein-protein interactions; structure-function relationship.
Copyright © 2018 Elsevier Ltd. All rights reserved.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Amino Acid Sequence
-
Binding Sites
-
Cell Cycle Proteins / chemistry*
-
Cell Cycle Proteins / genetics
-
Cell Cycle Proteins / metabolism
-
Cell Division
-
Cloning, Molecular
-
Crystallography, X-Ray
-
Escherichia coli / genetics
-
Escherichia coli / metabolism
-
Evolution, Molecular
-
Gene Expression
-
Genetic Vectors / chemistry
-
Genetic Vectors / metabolism
-
Microtubule Proteins / chemistry*
-
Microtubule Proteins / genetics
-
Microtubule Proteins / metabolism
-
Microtubule-Associated Proteins / chemistry*
-
Microtubule-Associated Proteins / genetics
-
Microtubule-Associated Proteins / metabolism
-
Microtubules / chemistry
-
Microtubules / ultrastructure
-
Models, Molecular
-
Nuclear Proteins / chemistry*
-
Nuclear Proteins / genetics
-
Nuclear Proteins / metabolism
-
Protein Binding
-
Protein Conformation, alpha-Helical
-
Protein Conformation, beta-Strand
-
Protein Interaction Domains and Motifs
-
Recombinant Proteins / chemistry
-
Recombinant Proteins / genetics
-
Recombinant Proteins / metabolism
-
Saccharomyces cerevisiae / chemistry*
-
Saccharomyces cerevisiae / metabolism
-
Saccharomyces cerevisiae / ultrastructure
-
Saccharomyces cerevisiae Proteins / chemistry*
-
Saccharomyces cerevisiae Proteins / genetics
-
Saccharomyces cerevisiae Proteins / metabolism
-
Sequence Alignment
-
Sequence Homology, Amino Acid
-
Spindle Apparatus / chemistry
-
Spindle Apparatus / ultrastructure
-
Structure-Activity Relationship
Substances
-
BIM1 protein, S cerevisiae
-
Bik1 protein, S cerevisiae
-
Cell Cycle Proteins
-
KAR9 protein, S cerevisiae
-
Microtubule Proteins
-
Microtubule-Associated Proteins
-
Nuclear Proteins
-
Recombinant Proteins
-
STU2 protein, S cerevisiae
-
Saccharomyces cerevisiae Proteins