Regulator of the tubulin polyglutamylase complex (TPGC) that controls cytoskeletal organization, nuclear shape, and cilium disassembly by balancing microtubule and actin assembly. Regulates the assembly and stability of the TPGC and thereby modulates polyglutamylation of the microtubule, which antagonizes MAP4 binding. Interacts with PCM1. Interacts with the complex TPGC. Binds to alpha-tubulin. Associated with microtubules. Expression in elevated in ciliated tissues/organs, including brain, spinal cord, kidney, eyes, ears and lateral line. Mutants survive to adulthood and produce offspring (PubMed:34782749). Embryos show a significant defect in heart looping, with an increased proportion of embryos without a looped heart (PubMed:34782749). the They have an increased percentage of ciliated cells and ciliary length in Kupffer's Vesicle, although these alterations are not observed in the ear, pronephros or neural tube (PubMed:34782749). Belongs to the CSTPP1 family.