The chemical reactions and pathways involving a cell wall arabinogalactan II glycoprotein, which is composed of a group of core protein of highly varying length and domain complexity. These are O-glycosylated at one or more hydroxyproline residues by arabinogalactan (AG) type II groups, which consist of (1->3)-beta-galactan and (1->6)-beta-linked galactan chains connected to each other by (1->3,1->6)-linked branch points, O-3 and O-6 positions substituted with terminal arabinosyl residues. Also, rhamnose, fucose, glucuronic and galacturonic acid can be present in the glycan structures.