2.A.94.1.7
Erd1 of 362 aas, possibly with 7 TMSs in a 1 + 2 + 3 + 1 TMS arrangement, where the first 3 TMSs are stronly hydrophobic, but the last 4 are only moderately hydrophobic. It is required for the retention of luminal endoplasmic reticulum/Golgi proteins and affects glycoprotein processing in the Golgi apparatus. Protein glycosylation in the Golgi is a sequential process that requires proper distribution of transmembrane glycosyltransferase enzymes in the appropriate Golgi compartments. Some of the cytosolic machinery required for the steady-state localization of some Golgi enzymes are known. Erd1 facilitates Golgi glycosyltransferase recycling by directly interacting with both the Golgi enzymes and the cytosolic receptor, Vps74 (Sardana et al. 2021). Loss of Erd1 function results in mislocalization of Golgi enzymes to the vacuole/lysosome. Erd1 forms an integral part of the recycling machinery while ensuring productive recycling of several early Golgi enzymes. It also determines how the localization of Golgi glycosyltransferases is spatially and temporally regulated (Sardana et al. 2021).