protein O-linked glycosylation via N-acetylgalactosamine obsolete protein O-linked glycosylation via threonine https://github.com/geneontology/go-ontology/issues/30517 true biological_process OBSOLETE. The glycosylation of protein via the O3 atom of peptidyl-threonine, forming O3-glycosyl-L-threonine; the most common forms are N-acetylgalactosaminyl, mannosyl, and galactosyl threonine. protein amino acid O-linked glycosylation via threonine GO:0018243 This term was obsoleted because it did not represent a specific process. It may correspond to protein O-linked GalNAcylation ; GO:0016266, protein O-linked glucosylation ; GO:0180059, protein O-linked galactosylation; GO:0180062, or protein O-linked mannosylation ; GO:0035269, all of which may be linked to a threonine in a protein. protein O-linked glycosylation via mannose protein O-linked glycosylation via glucose protein O-linked glycosylation via galactose