Enhances the tyrosine carboxypeptidase activity of VASH1 and VASH2, thereby promoting the removal of the C-terminal tyrosine residue of alpha-tubulin (  , ). This activity is critical for spindle function and accurate chromosome segregation during mitosis since microtubule detyronisation regulates mitotic spindle length and postioning . Also required to enhance the solubility and secretion of VASH1 and VASH2 ( ). Plays a role in axon and excitatory synapse formation .
Subcellular locations: Cytoplasm, Secreted, Cytoplasm, Cytoskeleton
Detected both intracellularly and extracellularly (By similarity). Within cells, localizes mainly to the apical part of the cell (By similarity).