DLO catabolism in yeast. OST transfers the glycan from DLO to N-glycosylate nascent proteins at an NXS/T motif (reaction 1). OST also hydrolyzes DLO to produce neutral glycans (reaction 2), which are transported into the cytoplasm and degraded. Reactions 1 and 2 generate dolichol-PP (dotted line), which is processed by Cax4 to dolichol-P and recycled for DLO biosynthesis. DLO also moves to the Golgi apparatus, likely by vesicular transport, where a polymannose chain (green beads) is added (reaction 3). The DLO-PPase Llp1, a small membrane protein (in red), cleaves both unmodified and mannosylated DLOs to release POSs and dolichol-P (reaction 4). The latter may be recycled to the ER.