Protein S-acylation is a dynamic lipid post-translational modification that can modulate the localization and activity of target proteins. In humans, the installation of the lipid onto target proteins is catalyzed by a family of 23 Asp-His-His-Cys domain-containing protein acyltransferases (DHHC-PATs). DHHCs are increasingly recognized as critical players in cellular signaling events and in human disease. However, progress elucidating the functions and mechanisms of DHHC "writers" has been hampered by a lack of chemical tools to perturb their activity in live cells. Herein, we report the synthesis and characterization of cyano-myracrylamide (CMA), a broad-spectrum DHHC family inhibitor with similar potency to 2-bromopalmitate (2BP), the most commonly used DHHC inhibitor in the field. Possessing an acrylamide warhead instead of 2BP's α-halo fatty acid, CMA inhibits DHHC family proteins in cellulo while demonstrating decreased toxicity and avoiding inhibition of the S-acylation eraser enzymes -two of the major weaknesses of 2BP. Our studies show that CMA engages with DHHC family proteins in cells, inhibits protein S-acylation, and disrupts DHHC-regulated cellular events. CMA represents an improved chemical scaffold for untangling the complexities of DHHC-mediated cell signaling by protein S-acylation. File list (2)download file view on ChemRxiv SA8_V28 changes accepted.pdf (16.08 MiB) download file view on ChemRxiv SI_Revision4.pdf (37.14 MiB)

<div><div><div><p>Protein S-acylation is a dynamic lipid post-translational modification that can modulate the localization and activity of target proteins. In humans, the installation of the lipid onto target proteins is catalyzed by a family of 23 Asp-His-His-Cys domain-containing protein acyltransferases (DHHC-PATs). DHHCs are increasingly recognized as critical players in cellular signaling events and in human disease. However, progress elucidating the functions and mechanisms of DHHC “writers” has been hampered by a lack of chemical tools to perturb their activity in live cells. Herein, we report the synthesis and characterization of PATi, a pan- DHHC inhibitor more potent than 2-bromopalmitate (2BP), the most commonly used DHHC inhibitor in the field. Possessing an acrylamide warhead, PATi pairs its gain in potency with decreases in both toxicity and inhibition of the S-acylation eraser enzymes – two of the major weaknesses of 2BP. Our studies show that PATi engages with DHHC family proteins in cells, inhibits protein S-acylation, and disrupts DHHC-regulated cellular events. PATi represents an improved chemical tool for untangling the complexities of DHHC-mediated cell signaling by protein S-acylation.</p></div></div></div>

The extracellular signal-regulated kinases (ERK1/2) are key effector proteins of the mitogen-activated protein kinase pathway, choreographing essential processes of cellular physiology. Critical in regulating these regulators are a patchwork of mechanisms, including post-translational modifications (PTMs) such as MEK-mediated phosphorylation. Here, we discover that ERK1/2 are subject to S-palmitoylation, a reversible lipid modification of cysteine residues, at C271/C254. Moreover, the levels of ERK1/2 S-acylation are modulated by epidermal growth factor (EGF) signaling, mirroring its phosphorylation dynamics, and palmitoylation-deficient ERK2 displays altered phosphorylation patterns at key sites. We find that chemical inhibition of either lipid addition or removal significantly alters ERK1/2’s EGF-triggered transcriptional program. We also identify a subset of “writer” protein acyl transferases (PATs) and an “eraser” acyl protein thioesterase (APT) that drive ERK1/2’s cycle of palmitoylation and depalmitoylation. Finally, we examine ERK1/2 S-acylation in a mouse model of metabolic syndrome, correlating changes in its lipidation levels with alterations in writer/eraser expression and solidifying the link between ERK1/2 activity, ERK1/2 lipidation, and organismal health. This study not only presents a previously undescribed mode of ERK1/2 regulation and a node to modulate MAPK pathway signaling in pathophysiological conditions, it also offers insight into the role of dynamic S-palmitoylation in cell signaling more generally.

<p>Protein <i>S</i>-acylation is a dynamic lipid post-translational modification that can modulate the localization and activity of target proteins. In humans, the installation of the lipid onto target proteins is catalyzed by a family of 23 Asp-His-His-Cys domain-containing protein acyltransferases (DHHC-PATs). DHHCs are increasingly recognized as critical players in cellular signaling events and in human disease. However, progress elucidating the functions and mechanisms of DHHC “writers” has been hampered by a lack of chemical tools to perturb their activity in live cells. Herein, we report the synthesis and characterization of <b>cyano-myracrylamide (CMA)</b>, a broad-spectrum DHHC family inhibitor with similar potency to 2-bromopalmitate (2BP), the most commonly used DHHC inhibitor in the field. Possessing an acrylamide warhead instead of 2BP’s α-halo fatty acid, <b>CMA </b>inhibits DHHC family proteins <i>in cellulo</i> while demonstrating decreased toxicity and avoiding inhibition<b> </b>of the <i>S-</i>acylation eraser enzymes – two of the major weaknesses of 2BP. Our studies show that <b>CMA </b>engages with DHHC family proteins in cells, inhibits protein <i>S-</i>acylation, and disrupts DHHC-regulated cellular events. <b>CMA</b> represents an improved chemical scaffold for untangling the complexities of DHHC-mediated cell signaling by protein <i>S</i>-acylation.</p>

Protein S-acylation is a dynamic lipid post-translational modification that can modulate the localization and activity of target proteins. In humans, the installation of the lipid onto target proteins is catalyzed by a family of 23 Asp-His-His-Cys domain-containing protein acyltransferases (DHHC-PATs). DHHCs are increasingly recognized as critical players in cellular signaling events and in human disease. However, progress elucidating the functions and mechanisms of DHHC "writers" has been hampered by a lack of chemical tools to perturb their activity in live cells. Herein, we report the synthesis and characterization of cyanomyracrylamide (CMA), a broad-spectrum DHHC family inhibitor with similar potency to 2bromopalmitate (2BP), the most commonly used DHHC inhibitor in the field. Possessing an acrylamide warhead instead of 2BP's α-halo fatty acid, CMA inhibits DHHC family proteins in cellulo while demonstrating decreased toxicity and avoiding inhibition of the S-acylation eraser enzymes -two of the major weaknesses of 2BP. Our studies show that CMA engages with DHHC family proteins in cells, inhibits protein S-acylation, and disrupts DHHC-regulated cellular events.CMA represents an improved chemical scaffold for untangling the complexities of DHHCmediated cell signaling by protein S-acylation.