InterPro domain: IPR027328

This entry represents the microtubule-associated protein RP/EB (MAPRE) family, including MAPRE1 (EB1), MAPRE2 (RP1, also known as EB2), MAPRE3 (EBF3, also known as EB3) and their homologues from eukaryotes. Despite their high protein sequence conservation, the individual EBs exhibit different regulatory and functional properties [ 1 ]. For instance, EB1 and EB3, but not EB2, promote persistent microtubule growth by suppressing catastrophes [ 2 ].

EB1 contains an N-terminal calponin homology (CH) domain that is responsible for the interaction with microtubules (MTs), and a C-terminal coiled coil domain that extends into a four-helix bundle, required for dimer formation [ 3 ]. Through their C-terminal sequences, EBs interact with most other known +TIPs (plus end tracking proteins) and recruit many of them to the growing MT ends [ 4 , 5 ]. EB1 is involved in MT anchoring at the centrosome and cell migration [ 5 ].

EB2 is highly expressed in pancreatic cancer cells, and seems to be involved in perineural invasion [ 6 ].

EB3 is specifically upregulated upon myogenic differentiation. Knockdown of EB3, but not that of EB1, prevents myoblast elongation and fusion into myotubes [ 7 ].

This entry also includes bZIP transcription factor hapX from the yeast Neosartorya fumigata , which is a transcription factor required for repression of genes during iron starvation [ 8 ].

1. Molecular insights into mammalian end-binding protein heterodimerization. J. Biol. Chem. 285, 5802-14
2. Mammalian end binding proteins control persistent microtubule growth. J. Cell Biol. 184, 691-706
3. Tracking the ends: a dynamic protein network controls the fate of microtubule tips. Nat. Rev. Mol. Cell Biol. 9, 309-22
4. Evidence that an interaction between EB1 and p150(Glued) is required for the formation and maintenance of a radial microtubule array anchored at the centrosome. Mol. Biol. Cell 13, 3627-45
5. EB1 and APC bind to mDia to stabilize microtubules downstream of Rho and promote cell migration. Nat. Cell Biol. 6, 820-30
6. The microtubule-associated protein MAPRE2 is involved in perineural invasion of pancreatic cancer cells. Int. J. Oncol. 35, 1111-6
7. EB3 regulates microtubule dynamics at the cell cortex and is required for myoblast elongation and fusion. Curr. Biol. 17, 1318-25
8. Aspergillus fumigatus AcuM regulates both iron acquisition and gluconeogenesis. Mol. Microbiol. 78, 1038-54