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Identification of palmitoylated mitochondrial proteins using a bio‐orthogonal azido‐palmitate analogue
Author(s) -
Kostiuk Morris A.,
Corvi Maria M.,
Keller Bernd O.,
Plummer Greg,
Prescher Jennifer A.,
Hangauer Matthew J.,
Bertozzi Carolyn R.,
Rajaiah Gurram,
Falck John R.,
Berthiaume Luc G.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.07-9199com
Subject(s) - palmitoylation , biochemistry , mitochondrion , thioester , mitochondrial matrix , cysteine , chemistry , acyltransferase , enzyme , fatty acid synthase , acyl coa , microbiology and biotechnology , biology , cytosol
Increased levels of circulating saturated free fatty acids, such as palmitate, have been implicated in the etiology of type II diabetes and cancer. In addition to being a constituent of glycerolipids and a source of energy, palmitate also covalently attaches to numerous cellular proteins via a process named palmi‐toylation. Recognized for its roles in membrane tethering, cellular signaling, and protein trafficking, palmi‐toylation is also emerging as a potential regulator of metabolism. Indeed, we showed previously that the acylation of two mitochondrial proteins at their active site cysteine residues result in their inhibition. Herein, we sought to identify other palmitoylated proteins in mitochondria using a nonradioactive bio‐orthogonal azido‐palmitate analog that can be selectively derivat‐ized with various tagged triarylphosphines. Our results show that, like palmitate, incorporation of azido‐palmi‐tate occurred on mitochondrial proteins via thioester bonds at sites that could be competed out by palmitoyl‐CoA. Using this method, we identified 21 putative palmitoylated proteins in the rat liver mitochondrial matrix, a compartment not recognized for its content in palmitoylated proteins, and confirmed the palmitoyl‐ation of newly identified mitochondrial 3‐hydroxy‐3‐methylglutaryl‐CoA synthase. We postulate that cova‐lent modification and perhaps inhibition of various mitochondrial enzymes by palmitoyl‐CoA could lead to the metabolic impairments found in obesity‐related diseases.—Kostiuk, M. A., Corvi, M. M., Keller, B. O., Plummer, G., Prescher, J. A., Hangauer, M. J., Bertozzi, C. R., Rajaiah, G., Falck, J. R., Berthiaume, L. G. Identification of palmitoylated mitochondrial proteins using a bio‐orthogonal azido‐palmitate analogue. FASEB J . 22, 721–732 (2008)