NINL is a 1,382 amino acid protein that localizes to both the cytoplasm and the centrosome and contains four EF-hand domains. Interacting with ?Tubulin, NLP is involved in microtubule organization in interphase cells and, when overexpressed, causes lysosomal dispersion and interferes with mitotic spindle assembly. NLP is subject to post-translational phosphorylation by Plk, an event which disrupts the association of NLP with centrosomes.