Microtubule-stabilizing protein that may play an important role during reorganization of microtubules during polarization and differentiation of epithelial cells. Associates with microtubules in a dynamic manner. May play a role in the formation of intercellular contacts. Colocalization with TRPV4 results in the redistribution of TRPV4 toward the membrane and may link cytoskeletal microfilaments. Interacts with TRPV4. Colocalized on microtubules. An intracellular redistribution is triggered during induction of keratinocyte terminal differentiation from microtubules with a perinuclear localization to cortical microtubules organized in spike-like bundles facing intercellular contacts. Highly expressed in the epithelial cells of the kidney tubules and in the absorptive cells of the intestine, and widely distributed in the testis. Expression correlates with the differentiation of certain epithelial cell types: in the adult intestine, more abundantly expressed in the differentiating than in the proliferative cell compartment. The expression clearly correlates with the degree of cellular apicobasal polarity. Expressed in lung, kidney, brain and fat. Colocalized with TRPV4 in ependymal cells, in the choroid plexus, in bronchial and renal cortical tubular cells. Widely expressed in excitable neuronal cells, vascular cells as well as in epithelial cells. In seminiferous epithelium, associated with the microtubule of the spermatid manchette. Expressed in several epithelia from 9.5 dpc onwards, with expression levels increasing during development. From 14.5 dpc onwards, found in some neuronal cells as well. The association with microtubules is regulated by phosphorylation during the cell cycle. During interphase only phosphorylated on serine. Phosphorylated on threonine in mitosis (By similarity). Belongs to the MAP7 family. Contaminating sequence. Potential poly-A sequence.