Essential for the formation and stability of microtubules (MTs) (PubMed:16890222, PubMed:31409757). Required for the organization of the mitotic spindle and for the proper attachment of kinetochores to MTs (PubMed:25789526). Promotes the recruitment of NUDC to the mitotic spindle for mitotic progression (PubMed:25789526). Homotrimer; self-association is mediated by the N-terminal coiled coil (PubMed:25740311). Interacts (via WD repeats) with NUDC (PubMed:25789526). Interacts with alpha- and beta-tubulin during mitosis (PubMed:31409757). Localizes to microtubules (MTs) during interphase with a significantly reduced affinity for MTs during mitosis. Phosphorylated during mitosis (PubMed:16890222). Phosphorylation at Ser-144 and Ser-146 promotes its dissociation from microtubules during mitosis which is required for efficient chromosome congression (PubMed:31409757). A chromosomal aberration involving EML4 has been identified in a subset of patients with non-small-cell lung carcinoma. This aberration leads to the production of a fusion protein between the N-terminus of EML4 and the C-terminus of ALK. It is unclear whether the fusion protein is caused by a simple inversion within 2p (inv(2)(p21p23)) or whether the chromosome translocation involving 2p is more complex. When tested in a heterologous system, the fusion protein EML4-ALK possesses transforming activity that is dependent on ALK catalytic activity, possibly due to spontaneous dimerization mediated by the EML4 moiety, leading to ALK kinase activation. Belongs to the WD repeat EMAP family. Contaminating sequence. Potential poly-A sequence. Truncated N-terminus.