ZO-2 is a scaffold at the centriole and mitotic spindle poles that enhances microtubule stability and supports the proper development of mitotic spindles and cilia.

Previous studies revealed the presence of several tight junction (TJ) proteins in the centrosome and their interaction with various centriolar proteins, prompting us to analyze whether this also applies to the TJ protein ZO-2. Here, we found that ZO-2 colocalizes with CEP164 in the distal appendage of the mother centriole and is also present in the pericentriolar region, mitotic spindle poles, the basal body of primary cilia, and the tail of spermatozoa. The absence of ZO-2 altered the cellular content of centriolar proteins CEP164, centriolin, and CEP135, but did not change the morphology of centrioles. ZO-2 depletion inhibits the development of astral and mitotic spindle microtubules expressing EB1. At the spindle poles, ZO-2 depletion increases the accumulation of NuMA while reducing the levels of kinesin KIF14 and the TPX2 scaffold, and the accumulation of the kinase p-Aurora, leading to a decrease in mitotic spindle length, microtubule instability, and abnormal chromosome congression. KIF14, NuMA, and p-Aurora co-immunoprecipitate with ZO-2, and NuMA and Aurora-A bind to different segments of ZO-2. At the ciliary basal body, ZO-2 depletion reduces the content of CEP164, KIF14, and IFT-B protein IFT57, while increasing the expression of p-Aurora and pAKT. These changes block primary cilium development and the response to Sonic Hedgehog signaling pathway stimulation. These results suggest that, rather than being a centrosomal architectural component, ZO-2 enhances microtubule stability and serves as a scaffold that facilitates the adequate accumulation of spindle pole and centriole proteins, allowing proper poleward spindle microtubule flux and cilia development.