Labeling and quantifying sites of protein palmitoylation (original) (raw)

Palmitoylated proteins: purification and identification

Nature Protocols, 2007

This proteomic protocol purifies and identifies palmitoylated proteins (i.e., S-acylated proteins) from complex protein extracts. The method relies on an acyl-biotinyl exchange chemistry in which biotin moieties are substituted for the thioester-linked protein acyl-modifications through a sequence of three in vitro chemical steps: (i) blockade of free thiols with N-ethylmaleimide; (ii) cleavage of the Cys-palmitoyl thioester linkages with hydroxylamine; and (iii) labeling of thiols, newly exposed by the hydroxylamine, with biotin-HPDP (Biotin-HPDP-N-[6-(Biotinamido)hexyl]-3¢-(2¢-pyridyldithio)propionamide. The biotinylated proteins are then affinity-purified using streptavidin-agarose and identified by multi-dimensional protein identification technology (MuDPIT), a high-throughput, tandem mass spectrometry (MS/MS)-based proteomic technology. MuDPIT also affords a semi-quantitative analysis that may be used to assess the gross changes induced to the global palmitoylation profile by mutation or drugs. Typically, 2-3 weeks are required for this analysis.

Posttranslational Protein Palmitoylation

Arteriosclerosis, Thrombosis, and Vascular Biology, 2007

osttranslational modification of proteins is the foundation of intracellular signaling. Without the ability to reversibly modify proteins and lipids, cells would be unable to react to signals received from their environment. Posttranslational modification of proteins usually, but not always, occurs after a protein has arrived at the appropriate subcellular location. In certain instances, however, such modifications serve as addresses to correctly target the protein within the cell.

Protein palmitoylation: a regulator of neuronal development and function

Nature Reviews Neuroscience, 2002

... Review. Nature Reviews Neuroscience 3, 791-802 (October 2002) | doi :10.1038/nrn940. Protein palmitoylation: a regulator of neuronal development and function. Alaa El-Din El-Husseini 1 & David S. Bredt 2 About the authors. Top of page Abstract. ...

Curation of the Mammalian Palmitoylome Indicates a Pivotal Role for Palmitoylation in Diseases and Disorders of the Nervous System and Cancers

PLOS Computational Biology, 2015

Palmitoylation involves the reversible posttranslational addition of palmitate to cysteines and promotes membrane binding and subcellular localization. Recent advancements in the detection and identification of palmitoylated proteins have led to multiple palmitoylation proteomics studies but these datasets are contained within large supplemental tables, making downstream analysis and data mining time-consuming and difficult. Consequently, we curated the data from 15 palmitoylation proteomics studies into one compendium containing 1,838 genes encoding palmitoylated proteins; representing approximately 10% of the genome. Enrichment analysis revealed highly significant enrichments for Gene Ontology biological processes, pathway maps, and process networks related to the nervous system. Strikingly, 41% of synaptic genes encode a palmitoylated protein in the compendium. The top disease associations included cancers and diseases and disorders of the nervous system, with Schizophrenia, HD, and pancreatic ductal carcinoma among the top five, suggesting that aberrant palmitoylation may play a pivotal role in the balance of cell death and survival. This compendium provides a much-needed resource for cell biologists and the palmitoylation field, providing new perspectives for cancer and neurodegeneration.

SwissPalm: Protein Palmitoylation database

F1000Research, 2015

Protein S-palmitoylation is a reversible post-translational modification that regulates many key biological processes, although the full extent and functions of protein S-palmitoylation remain largely unexplored. Recent developments of new chemical methods have allowed the establishment of palmitoyl-proteomes of a variety of cell lines and tissues from different species. As the amount of information generated by these high-throughput studies is increasing, the field requires centralization and comparison of this information. Here we present SwissPalm (http://swisspalm.epfl.ch), our open, comprehensive, manually curated resource to study protein S-palmitoylation. It currently encompasses more than 5000 S-palmitoylated protein hits from seven species, and contains more than 500 specific sites of S-palmitoylation. SwissPalm also provides curated information and filters that increase the confidence in true positive hits, and integrates predictions of S-palmitoylated cysteine scores, or...

Protein palmitoylation in cancer: molecular functions and therapeutic potential

Molecular oncology, 2022

Protein S-palmitoylation (hereinafter referred to as protein palmitoylation) is a reversible lipid posttranslational modification catalyzed by the zinc finger DHHC-type containing (ZDHHC) protein family. The reverse reaction, depalmitoylation, is catalyzed by palmitoyl-protein thioesterases (PPTs), including acyl-protein thioesterases (APT1/2), palmitoyl protein thioesterases (PPT1/ 2), or alpha/beta hydrolase domain-containing protein 17A/B/C (ABHD17A/B/ C). Proteins encoded by several oncogenes and tumor suppressors are modified by palmitoylation, which enhances the hydrophobicity of specific protein subdomains, and can confer changes in protein stability, membrane localization, protein–protein interaction, and signal transduction. The importance for protein palmitoylation in tumorigenesis has just started to be elucidated in the past decade; palmitoylation appears to affect key aspects of cancer, including cancer cell proliferation and survival, cell invasion and metastasis, and antitumor immunity. Here we review the current literature on protein palmitoylation in the various cancer types, and discuss the potential of targeting of palmitoylation enzymes or palmitoylated proteins for tumor treatment.

Biochemical Characterization of a Palmitoyl Acyltransferase Activity That Palmitoylates Myristoylated Proteins

Journal of Biological Chemistry, 1995

Dynamic regulation of signal transduction by reversible palmitoylation-depalmitoylation cycles has been recently described. However, further understanding of fatty acylation reactions has been hampered by our lack of knowledge about the specific transferases and thioesterases involved. Here, we describe an assay for the palmitoyl acyltransferase (PAT) that palmitoylates "myrGlyCys" containing members of the Src family of protein tyrosine kinases (PTKs). Since N-myristoylation of Fyn PTK, a member of the Src family, has been shown to be a prerequisite for palmitoylation, a new single plasmid vector that allows overexpression of myristoylated Fyn substrate in Escherichia coli was developed. Purified myristoylated protein substrates were incubated with [ 125 I]iodopalmitoyl CoA, a palmitoyl CoA analog, in the presence of bovine brain lysates. Transfer of radiolabel to the Fyn substrate was detected by SDSpolyacrylamide gel electrophoresis and autoradiography. This assay was used to partially purify and characterize PAT activity from bovine brain. Here, we demonstrate that PAT is a membrane-bound enzyme, which palmitoylates myristoylated Fyn substrates containing a cysteine residue in position three. The PAT activity attached palmitate to Fyn proteins via a thioester linkage and exhibited a fatty acyl CoA preference for long chain fatty acids. It is likely that palmitoylation of Fyn and other Src family members by PAT regulates PTK localization and signaling functions.