A group from Osaka University etc. has found that Rab11 (a regulator of membrane vesicle transport via recycling endosomes) is deeply involved in N-glycan modification.
https://www.jbc.org/article/S0021-9258(21)00126-5/fulltext
Glycan modification is controlled by glycosyltransferases present in the endoplasmic reticulum and Golgi bodies. Therefore, if each glycosyltransferase is not in an appropriate position, the glycan modification is not performed correctly. Unfortunately, the mechanism for transporting glycosyltransferases to the correct positions is not known.
The authors have found that Rab11, a regulator of membrane vesicle transport, was heavily involved in the modification of α2-3Sia. In cells that knocked out Rab11, the modification of α2-3Sia was greatly upregulated, and thereby it was found that Rab11 negatively controlled the α2-3Sia modification by transporting the glycosyltransferase ST3GAL4 out of the Golgi body region.
The figure below shows the role of Rab11 in a healthy state.
