Ganglioside glycosyltransferases are S-acylated at conserved cysteine residues involved in homodimerisation

CHUMPEN RAMIREZ, SABRINA; RUGGIERO, FERNANDO M.; DANIOTTI, JOSE LUIS; VALDEZ TAUBAS, JAVIER

BIOCHEMICAL JOURNAL

PORTLAND PRESS LTD

Año: 2017 vol. 474 p. 2803 - 2803

0264-6021

anglioside glycosyltransferases (GGTs) are type II membrane proteins bearing a short N-terminal cytoplasmic tail, a transmembrane domain (TMD), and a lumenal catalytic domain. The expression and activity of these enzymes largely determine the quality of the glycolipids that decorate mammalian cell membranes. Many glycosyltransferases (GTs) are themselves glycosylated, and this is important for their proper localisation, but few if any other post-translational modifications of these proteins have been reported. Here, we show that the GGTs, ST3Gal-V, ST8Sia-I, and β4GalNAcT-I are S-acylated at conserved cysteine residues located close to the cytoplasmic border of their TMDs. ST3Gal-II, a GT that sialylates glycolipids and glycoproteins, is also S-acylated at a conserved cysteine located in the N-terminal cytoplasmic tail. Many other GTs also possess cysteine residues in their cytoplasmic regions, suggesting that this modification occurs also on these GTs. S-acylation, commonly know