MAPRE1 (Microtubule-associated protein, RP/EB family, member 1)

2004-11-01   Jennifer S Tirnauer 

Center for Molecular Medicine, University of Connecticut Health Center, 263 Farmington Avenue, E1032, Farmington, CT 06030-3101, USA


Atlas Image
EB1-GFP fluorescence on polymerizing microtubule plus ends in a living PtK1 cell.



22 Kb genomic locus, 5 introns


2540 bp open reading frame


Atlas Image


268 amino acids; 35 kDa; EB1 was cloned in yeast two-hybrid screen as binding partner for the tumor suppressor APC (Adenomatous Polyposis Coli); EB1 is a microtubule plus end tracking protein (+tip). It contains a calponin homology domain and a leucine zipper


EB1 is ubiquitously expressed. Protein levels remain similar throughout the cell cycle.


EB1 targets to the plus ends of microtubules when they are polymerizing, producing a "comet tail" pattern. (Figure 1). The mechanism is treadmilling, in which new subunits are continually added at the tip. EB1 also shows additional weak binding to the microtubule lattice (along the length of the microtubule). EB1 targets to kinetochores moving anti-poleward. This is suspected to be due to binding to kinetochore microtubule plus ends rather than the kinetochore itself. Through its carboxyl terminus, EB1 localizes to centrosomes and spindle poles.


  • The primary function identified to date is regulation of microtubule dynamic instability. Microtubules dynamically convert between growth (polymerization) and shrinkage (depolymerization). The transition from growth to shrinkage is called catastrophe, while the conversion from shrinkage to growth is called rescue. Microtubules also pause in their polymerization. EB1 reduces these pauses and reduces the frequency of catastrophes. EB1 increases the frequency of rescues. The net result is more stable, longer microtubules. This effect is predominantly seen during mitosis.
  • EB1 is important in maintaining the structure of the mitotic spindle. This is thought to be mediated by its effects on spindle microtubule dynamic instability.
  • EB1 is important in spindle positioning within the cell. This is thought to be due to its effects on astral microtubule dynamic instability. In budding yeast, EB1 also plays a role in positioning the mitotic spindle through the bud neck. In this case, it is through microtubule dynamics as well direct binding to a protein at the bud tip, creating a physical link between the microtubule end and the cell cortex.
  • EB1 plays a role in linking kinetochores to kinetochore microtubules, which is important for chromosome stability. It is not known whether it regulates kinetochore microtubule dynamics or end-on attachment.
  • EB1 also has an independent role in anchoring microtubule minus ends to centrosomes
  • Protein-protein interactions: Adenomatous Polyposis Coli (APC) tumor suppressor, polymerized tubulin (microtubules), p150glued/dynactin, CLIP-170, mDia, Pin2/TRF1, RhoGEF2 (drosophila), shortstop (drosophila)
  • Homology



    none known

    Implicated in

    Entity name
    Colon cancer
    Truncation of the Adenomatous Polyposis Coli (APC) protein is seen in Familial Adenomatous Polyposis (FAP) as well as most sporadic colon cancers. EB1 binds to the APC C-terminus, so its binding is lost in most truncations. Also lost are other APC binding partners including the transcription factor beta-catenin. The role of APC as a tumor suppressor is thought to be through the beta-catenin pathway. Some evidence in the mouse suggests that this is true.
    However, there is increasing evidence that connections between APC and the cytoskeleton are important in cell migration, which could have an important role in colon cancer. One Italian FAP family has been reported in which APC is truncated distal to the beta-catenin binding site but including the EB1 binding site. There is no direct evidence of EB1 mutation in colon cancer, and a single report found no evidence of somatic mutations by reverse transcriptase single-strand conformational polymorphism (SSCP) analysis in 21 sporadic colorectal cancers and seven colorectal adenomas.
    Entity name
    A single report showed that EB1 is transcriptionally elevated in pediatric meduloblastoma. There is no direct evidence of EB1 mutation in meduloblastoma.



    none known


    Pubmed IDLast YearTitleAuthors
    107738852000Regulation and function of the interaction between the APC tumour suppressor protein and EB1.Askham JM et al
    123887622002Evidence that an interaction between EB1 and p150(Glued) is required for the formation and maintenance of a radial microtubule array anchored at the centrosome.Askham JM et al
    119508772002Dissecting interactions between EB1, microtubules and APC in cortical clusters at the plasma membrane.Barth AI et al
    102260311999The APC-associated protein EB1 associates with components of the dynactin complex and cytoplasmic dynein intermediate chain.Berrueta L et al
    145146682003Characterization of functional domains of human EB1 family proteins.Bu W et al
    127896612003CLIP-170 interacts with dynactin complex and the APC-binding protein EB1 by different mechanisms.Goodson HV et al
    128577352003Crystal structure of the amino-terminal microtubule-binding domain of end-binding protein 1 (EB1).Hayashi I et al
    98239791998Absence of somatic alterations of the EB1 gene adenomatous polyposis coli-associated protein in human sporadic colorectal cancers.Jaïs P et al
    101887311999EB/RP gene family encodes tubulin binding proteins.Juwana JP et al
    107311462000Molecular linkage underlying microtubule orientation toward cortical sites in yeast.Korinek WS et al
    107311472000Positioning of the mitotic spindle by a cortical-microtubule capture mechanism.Lee L et al
    126865972003The microtubule plus-end proteins EB1 and dynactin have differential effects on microtubule polymerization.Ligon LA et al
    149702572004Adenomatous polyposis coli and EB1 localize in close proximity of the mother centriole and EB1 is a functional component of centrosomes.Louie RK et al
    146148262003A novel localization pattern for an EB1-like protein links microtubule dynamics to endomembrane organization.Mathur J et al
    108990062000The dynamic behavior of the APC-binding protein EB1 on the distal ends of microtubules.Mimori-Kiyosue Y et al
    100306711998EB1, a protein which interacts with the APC tumour suppressor, is associated with the microtubule cytoskeleton throughout the cell cycle.Morrison EE et al
    96240071998A cytokinesis checkpoint requiring the yeast homologue of an APC-binding protein.Muhua L et al
    114704132001Critical role for the EB1 and APC interaction in the regulation of microtubule polymerization.Nakamura M et al
    92336231997RP1, a new member of the adenomatous polyposis coli-binding EB1-like gene family, is differentially expressed in activated T cells.Renner C et al
    122138352002Drosophila EB1 is important for proper assembly, dynamics, and positioning of the mitotic spindle.Rogers SL et al
    154984902004Drosophila RhoGEF2 associates with microtubule plus ends in an EB1-dependent manner.Rogers SL et al
    93986841997BIM1 encodes a microtubule-binding protein in yeast.Schwartz K et al
    76067121995APC binds to the novel protein EB1.Su LK et al
    111618072001Characterization of human MAPRE genes and their proteins.Su LK et al
    128420072003Shortstop recruits EB1/APC1 and promotes microtubule assembly at the muscle-tendon junction.Subramanian A et al
    123887612002EB1-microtubule interactions in Xenopus egg extracts: role of EB1 in microtubule stabilization and mechanisms of targeting to microtubules.Tirnauer JS et al
    153112822004EB1 and APC bind to mDia to stabilize microtubules downstream of Rho and promote cell migration.Wen Y et al

    Other Information

    Locus ID:

    NCBI: 22919
    MIM: 603108
    HGNC: 6890
    Ensembl: ENSG00000101367


    dbSNP: 22919
    ClinVar: 22919
    TCGA: ENSG00000101367


    Gene IDTranscript IDUniprot

    Expression (GTEx)



    PathwaySourceExternal ID
    Organelle biogenesis and maintenanceREACTOMER-HSA-1852241
    Cilium AssemblyREACTOMER-HSA-5617833
    Anchoring of the basal body to the plasma membraneREACTOMER-HSA-5620912
    Signal TransductionREACTOMER-HSA-162582
    Signaling by Rho GTPasesREACTOMER-HSA-194315
    RHO GTPase EffectorsREACTOMER-HSA-195258
    RHO GTPases Activate ForminsREACTOMER-HSA-5663220
    Cell CycleREACTOMER-HSA-1640170
    Cell Cycle, MitoticREACTOMER-HSA-69278
    Mitotic G2-G2/M phasesREACTOMER-HSA-453274
    G2/M TransitionREACTOMER-HSA-69275
    Regulation of PLK1 Activity at G2/M TransitionREACTOMER-HSA-2565942
    Centrosome maturationREACTOMER-HSA-380287
    Recruitment of mitotic centrosome proteins and complexesREACTOMER-HSA-380270
    Loss of proteins required for interphase microtubule organization from the centrosomeREACTOMER-HSA-380284
    Loss of Nlp from mitotic centrosomesREACTOMER-HSA-380259
    M PhaseREACTOMER-HSA-68886
    Mitotic PrometaphaseREACTOMER-HSA-68877
    Resolution of Sister Chromatid CohesionREACTOMER-HSA-2500257
    Mitotic Metaphase and AnaphaseREACTOMER-HSA-2555396
    Mitotic AnaphaseREACTOMER-HSA-68882
    Separation of Sister ChromatidsREACTOMER-HSA-2467813
    The role of GTSE1 in G2/M progression after G2 checkpointREACTOMER-HSA-8852276
    AURKA Activation by TPX2REACTOMER-HSA-8854518

    Protein levels (Protein atlas)

    Not detected


    Pubmed IDYearTitleCitations
    192552452009Mammalian end binding proteins control persistent microtubule growth.149
    160302542005APC and EB1 function together in mitosis to regulate spindle dynamics and chromosome alignment.93
    191266802009Microtubule plus-end tracking by CLIP-170 requires EB1.86
    128577352003Crystal structure of the amino-terminal microtubule-binding domain of end-binding protein 1 (EB1).71
    217683262011EB1 and EB3 promote cilia biogenesis by several centrosome-related mechanisms.49
    206967102010KIF17 stabilizes microtubules and contributes to epithelial morphogenesis by acting at MT plus ends with EB1 and APC.45
    227483192012Phosphoregulation of STIM1 leads to exclusion of the endoplasmic reticulum from the mitotic spindle.45
    217376852011Kif18B interacts with EB1 and controls astral microtubule length during mitosis.43
    215623672011Epigenetic regulation of microRNA-10b and targeting of oncogenic MAPRE1 in gastric cancer.39
    224678762012Multisite phosphorylation disrupts arginine-glutamate salt bridge networks required for binding of cytoplasmic linker-associated protein 2 (CLASP2) to end-binding protein 1 (EB1).39


    Jennifer S Tirnauer

    MAPRE1 (Microtubule-associated protein, RP/EB family, member 1)

    Atlas Genet Cytogenet Oncol Haematol. 2004-11-01

    Online version: