Metallocarboxypeptidase that mediates deglutamylation of tubulin and non-tubulin target proteins (PubMed:21074048). Catalyzes the removal of polyglutamate side chains present on the gamma-carboxyl group of glutamate residues within the C-terminal tail of tubulin protein (PubMed:21074048). Specifically cleaves tubulin long-side-chains, while it is not able to remove the branching point glutamate (PubMed:21074048). Also catalyzes the removal of polyglutamate residues from the carboxy-terminus of non-tubulin proteins such as MYLK (PubMed:21074048). (L-glutamyl)(n+1)-gamma-L-glutamyl-L-glutamyl-[protein] + H2O = (L-glutamyl)(n)-gamma-L-glutamyl-L-glutamyl-[protein] + L-glutamate C-terminal L-alpha-aminoacyl-L-glutamyl-L-glutamyl-[tubulin] + H2O = C-terminal L-alpha-aminoacyl-L-glutamyl-[tubulin] + L-glutamate Binds 1 zinc ion per subunit. Interacts with MYLK (PubMed:21074048). Interacts with TCF4 (By similarity). Widely expressed at low level. Expressed in eye, muscle, pituitary, testis and to a lower extent in brain. Belongs to the peptidase M14 family.