Metallocarboxypeptidase that mediates deglutamylation of tubulin and non-tubulin target proteins (PubMed:21074048, PubMed:20519502, PubMed:24022482, PubMed:26829768). Catalyzes the removal of polyglutamate side chains present on the gamma-carboxyl group of glutamate residues within the C-terminal tail of alpha- and beta-tubulin (PubMed:21074048, PubMed:20519502, PubMed:24022482). Cleaves alpha- and gamma-linked polyglutamate tubulin side-chain, as well as the branching point glutamate (PubMed:21074048, PubMed:24022482). Also catalyzes the removal of alpha-linked glutamate residues from the carboxy-terminus of alpha-tubulin (PubMed:24022482). Mediates deglutamylation of nucleotidyltransferase CGAS, leading to CGAS antiviral defense response activation (PubMed:26829768). gamma-L-glutamyl-L-glutamyl-[protein] + H2O = L-glutamate + L-glutamyl-[protein] (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-[tubulin] + H2O = C-terminal L-alpha-aminoacyl-[tubulin] + 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. Colocalizes with alpha-tubulin in the mitotic spindle and with midbody microtubules in the intercellular bridges formed during cytokinesis (By similarity). Mainly cytoplasmic. Slight accumulation in the nucleus is observed (PubMed:17244818). Widely expressed. Highly expressed in testis, and moderately in pituitary, brain, eye and kidney. Mice are more vulnerable to DNA virus infection due to impaired immune response. Belongs to the peptidase M14 family. Truncated N-terminus.