Plus-end tracking protein (+TIP) that binds to the plus-end of microtubules and regulates the dynamics of the microtubule cytoskeleton. Promotes cytoplasmic microtubule nucleation and elongation. Involved in mitotic spindle positioning by stabilizing microtubules and promoting dynamic connection between astral microtubules and the cortex during mitotic chromosome segregation. Also acts as a regulator of minus-end microtubule organization: interacts with the complex formed by AKAP9 and PDE4DIP, leading to recruit CAMSAP2 to the Golgi apparatus, thereby tethering non-centrosomal minus-end microtubules to the Golgi, an important step for polarized cell movement. Promotes elongation of CAMSAP2-decorated microtubule stretches on the minus-end of microtubules. Acts as a regulator of autophagosome transport via interaction with CAMSAP2 (By similarity). May play a role in cell migration (By similarity). Homodimer. Heterodimer with MAPRE3. Interacts with DCTN1, DCTN2, TERF1 and dynein intermediate chain (By similarity). Interaction with DIAPH1 and DIAPH2 (By similarity). Interacts with APC (via C-terminal domain), CLASP2, DST, KIF2C and STIM1; probably required for their targeting to the growing microtubule plus ends. Interacts with MTUS2; interaction is direct and probably targets MTUS2 to microtubules. Interacts with APC2. Interacts with CLASP1. Interacts with CDK5RAP2 (By similarity). Interacts with MACF1. Interacts with RABL2/RABL2A; binds preferentially to GTP-bound RABL2. Interacts with KCNAB2 (By similarity). Interacts (via C-terminus) with CLIP1. Interacts with SLAIN2 and SLAIN1. Interacts with KIF18B; this interaction is required for efficient accumulation of KIF18B at microtubule plus ends. Interacts with MISP. Interacts with KNSTRN. Interacts with NCKAP5L. Interacts with CAMSAP2. Interacts with PDE4DIP isoform 13/MMG8/SMYLE; this interaction is required for its recruitment to the Golgi apparatus. Forms a pericentrosomal complex with AKAP9, CDK5RAP2 and PDE4DIP isoform 13/MMG8/SMYLE; within this complex, MAPRE1 binding to CDK5RAP2 may be mediated by PDE4DIP (By similarity). Interacts with AKNA (By similarity). Interacts with GAS2L1, GAS2L2, and GAS2L3 (By similarity). Associated with the microtubule growing distal tips. Recruitment to the Golgi apparatus requires the presence of PDE4DIP isoform 13/MMG8/SMYLE. Composed of two functionally independent domains. The N-terminal domain forms a hydrophobic cleft involved in microtubule binding and the C-terminal is involved in the formation of mutually exclusive complexes with APC and DCTN1. Acetylation at Lys-220 by KAT2B/PCAF promotes dynamic kinetochore-microtubule interactions in early mitosis. Crotonylated by KAT5 during mitosis, promoting astral microtubule plasticity and dynamic connection between astral microtubules and the cortex during mitotic chromosome segregation, thereby ensuring accurate spindle positioning in mitosis. Decrotonylated by HDAC3. Belongs to the MAPRE family.