Subunit of the tubulin polyglutamylase complex (TPGC). The complex mediates cilia and flagella polyglutamylation which is essential for their biogenesis and motility. Part of the neuronal tubulin polyglutamylase complex which contains TPGS1, TPGS2, TTLL1, LRRC49 and NICN1 (Probable). Interacts with PCM1; TTLL1, TPGS1, TPGS2 and LRRC49 (PubMed:34782749). Associated with microtubules.