Marin EP, Derakhshan B, Lam TT, Davalos A, Sessa WC. Endothelial cell palmitoylproteomic identifies novel lipid-modified targets and potential substrates for protein acyl transferases.
Circ Res 2012;
110:1336-44. [PMID:
22496122 PMCID:
PMC3428238 DOI:
10.1161/circresaha.112.269514]
[Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 04/02/2012] [Indexed: 11/16/2022]
Abstract
RATIONALE
Protein S-palmitoylation is the posttranslational attachment of a saturated 16-carbon palmitic acid to a cysteine side chain via a thioester bond. Palmitoylation can affect protein localization, trafficking, stability, and function. The extent and roles of palmitoylation in endothelial cell (EC) biology is not well-understood, partly because of technological limits on palmitoylprotein detection.
OBJECTIVE
To develop a method using acyl-biotinyl exchange technology coupled with mass spectrometry to globally isolate and identify palmitoylproteins in ECs.
METHODS AND RESULTS
More than 150 putative palmitoyl proteins were identified in ECs using acyl-biotinyl exchange and mass spectrometry. Among the novel palmitoylproteins identified is superoxide dismutase-1, an intensively studied enzyme that protects all cells from oxidative damage. Mutation of cysteine-6 prevents palmitoylation, leads to reduction in superoxide dismutase-1 activity in vivo and in vitro, and inhibits nuclear localization, thereby supporting a functional role for superoxide dismutase-1 palmitoylation. Moreover, we used acyl-biotinyl exchange to search for substrates of particular protein acyl transferases in ECs. We found that palmitoylation of the cell adhesion protein platelet endothelial cell adhesion molecule-1 is dependent on the protein acyl transferase ZDHHC21. We show that knockdown of ZDHHC21 leads to reduced levels of platelet endothelial cell adhesion molecule-1 at the cell surface.
CONCLUSIONS
Our data demonstrate the utility of EC palmitoylproteomics to reveal new insights into the role of this important posttranslational lipid modification in EC biology.
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