Sialic acid O-acetylation occurs in the Golgi apparatus and is catalyzed by CASD1, a multi-pass transmembrane protein. Here, the authors reveal that SLC33A1 delivers acetyl-CoA to the luminal catalytic domain of CASD1, while a catalytic transmembrane tunnel enables SLC33A1-independent O-acetylation.
- Malena Albers
- Lydia Bosse
- Martina Mühlenhoff
