GAPDH is tethered to axonal transport vesicles by S-acylation

Vesicle movement along axonal microtubules in neurons requires the ATP-dependent molecular motors dynein and kinesin. Fast axonal transport is fueled by ATP, provided by vesicle-associated glycolytic enzymes, but how these predicted soluble enzymes attach to vesicles in unclear. One potential mechanism is the protein lipid modification S-acylation, which involves the addition of long chain fatty acids to protein cysteine residues mediated by the ZDHHC (Asp-His-His-Cys) family of protein S-acyltransferases. Among the many effects this lipid modification imparts is an increase in protein localization to membranes. We found that eight of the ten glycolytic enzymes are S-acylated in the brain. Of the 10 glycolytic enzymes, we focused on glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as it is the first enzyme of the payoff phase of glycolysis. GAPDH is S-acylated on cysteine 247 by ZDHHC5 and ZDHHC17. Importantly, C247 point mutation impairs GAPDH association with vesicles in hippocampal neurons. Investigating the role of S-acylation in glycolytic enzyme localization will lead to novel insights into neuronal transport mechanisms and may also shed light on neurodegenerative disease pathology and potential drug targets.