Human SND2 mediates ER targeting of GPI ‐anchored proteins with low hydrophobic GPI attachment signals

Over 100 glycosylphosphatidylinositol ‐anchored proteins (GPI‐APs) are encoded in the mammalian genome. It is not well understood how these proteins are targeted and translocated to the endoplasmic reticulum (ER). Here, we reveal that many GPI‐APs, such as CD59, CD55, and CD109, utilize human SND2 (hSND2)‐dependent ER targeting machinery. We also found that signal recognition particle receptors seem to cooperate with hSND2 to target GPI‐APs to the ER. Both the N‐terminal signal sequence and C‐terminal GPI attachment signal of GPI‐APs contribute to ER targetingvia the hSND2 ‐dependent pathway. Particularly, the hydrophobicity of the C‐terminal GPI attachment signal acts as the determinant of hSND2 dependency. Our results explain the route and mechanism of the ER targeting of GPI‐APs in mammalian cells.

Source: FEBS Letters - April 24, 2021 Category: Biochemistry Authors: Jing Yang, Tetsuya Hirata, Yi ‐Shi Liu, Xin‐Yu Guo, Xiao‐Dong Gao, Taroh Kinoshita, Morihisa Fujita, Sandro Sonnino Tags: Research Article Source Type: research