Neural palmitoyl-proteomics reveals dynamic synaptic palmitoylation

Abstract

Summary Palmitoylation regulates diverse aspects of neuronal protein trafficking and function. Here, a global characterization of the neuronal palmitoyl-proteome identifies most of the known neuronal palmitoyl-proteins (PPs), 68 in total, plus over 200 new PP candidates, with additional testing confirming palmitoylation for 21 of these candidates. New PPs include neurotransmitter receptors, transporters, adhesion molecules, scaffolding proteins, as well as SNAREs and other vesicular trafficking proteins. Of particular interest is a finding of palmitoylation for a brain-specific Cdc42 splice variant. The palmitoylated Cdc42 isoform (Cdc42-palm) differs from the canonical, prenylated form (Cdc42-prenyl) both with regard to localization and function: Cdc42-palm, concentrates in dendritic spines and plays a special role in inducing these post-synaptic structures. Finally, assessing palmitoylation dynamics in drug-induced activity paradigms finds rapidly induced changes both for Cdc42 as well as for other synaptic PPs, suggesting that palmitoylation may participate broadly in the activity-driven changes that shape synapse morphology and function.

Postmortem Brain: An Underutilized Substrate for Studying Severe Mental Illness

“…One promising biochemical technique has been developed that may permit interrogation of palmitoylation in postmortem samples. The biotin switch assay selectively replaces palmitoyl groups with biotin, which may then be detected with streptavidin conjugated to a reporter molecule (Drisdel and Green, 2004;Kang et al, 2008). A similar strategy may be feasible for the detection of nitrosyl groups, using ascorbate to reduce nitrosylated Cys residues and labeling of reduced residues with biotin (Jaffrey, 2005;.…”

Molecular basis of the alternative recruitment of GABAA versus glycine receptors through gephyrin

“…Phosphorylation [29][30][31][32] , palmitoylation 33,34 and acetylation 35,36 of gephyrin have been reported and these post-translational modifications have been shown to affect the structure, trafficking, half-life and importantly the ability of gephyrin to interact with partner proteins. To test whether the identified short GABA A Rderived peptide fragments a9-11 also mediate binding to native full-length gephyrin comprising post-translational modifications, the peptides were covalently immobilized on iodoacetyl-activated beads and subsequently incubated with mouse brain lysates.…”

Gephyrin: a central GABAergic synapse organizer

“…46 In addition to phosphorylation, gephyrin is subject to palmitoylation 47 (Figure 1). Gephyrin was initially postulated as a potential substrate for palmitoyl acyltransferase, 48 and later work confirmed that cysteine 212 and cysteine 284 are palmitoylated by the enzyme, Asp-His-His-Cys (DHHC)-12, which is localized to the Golgi apparatus and dendritic shaft, and directly interacts with gephyrin. 47 The DHHC-12-mediated palmitoylation of gephyrin, which is regulated by GABA A receptor activity, is essential for the postsynaptic membrane association and clustering of gephyrin, and has been shown to increase inhibitory synaptic transmission.…”