Polyglutamylase which modifies tubulin, generating polyglutamate side chains on the gamma-carboxyl group of specific glutamate residues within the C-terminal tail of tubulin. Preferentially mediates ATP-dependent initiation step of the polyglutamylation reaction over the elongation step. Preferentially modifies the alpha-tubulin tail over a beta-tail (By similarity). Required for CCSAP localization to both polyglutamylated spindle and cilia microtubules . Increases the effects of transcriptional coactivator NCOA2/TIF2 in glucocorticoid receptor-mediated repression and induction and in androgen receptor-mediated induction .
Subcellular locations: Cell projection, Cilium, Cytoplasm, Cytoskeleton, Cilium basal body, Nucleus, Cytoplasm
Localized to the base of the connecting cilium between the basal body and the adjacent daughter centriole of the cilium. In osteosarcoma cells, found in both cytoplasm and nucleus in the absence of steroid but located exclusively in the nucleus in the presence of steroid.
Expressed in the retina, found in the rod and cone photoreceptors (at protein level). Widely expressed with highest levels in heart and skeletal muscle and low levels in other tissues.