In vivo and in vitro methylation of the elongation factor EF-Tu from<i>Euglena gracilis</i>chloroplast

Toledo, HÃ©ctor; Jerez, Carlos A.

doi:10.1111/j.1574-6968.1990.tb03830.x

Cited by 5 publications

(1 citation statement)

References 26 publications

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“…Post-translational N-modification of lysine residues has also been found to occur in eEF1A of all organisms studied to date. Methylated N-⑀-lysine residues have been identified in the prokaryotic counterpart EF1A (formerly EF-Tu) of Escherichia coli (34) and Salmonella typhimurium (35), as well as in the protist Euglena gracilis (36). Eukaryotic organisms including the fungus Mucor racemosus (37,38), brine shrimp Artemia salina (39), yeast S. cerevisiae (16), and rabbit (40) all contain eEF1A proteins that have been shown to be methylated on N-⑀-lysine residues as well.…”

Section: Methylesterification Of Eef1a Is Rapidly Reversible In Intactmentioning

confidence: 99%

A Novel Post-translational Modification of Yeast Elongation Factor 1A

Zobel-Thropp¹,

Yang²,

Machado³

et al. 2000

Journal of Biological Chemistry

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Protein methylation reactions can play important roles in cell physiology. After labeling intact Saccharomyces cerevisiae cells with S-adenosyl-L-[methyl-3 H]methionine, we identified a major methylated 49-kDa polypeptide containing [ 3 H]methyl groups in two distinct types of linkages. Peptide sequence analysis of the purified methylated protein revealed that it is eukaryotic elongation factor 1A (eEF1A, formerly EF-1␣), the protein that forms a complex with GTP and aminoacyltRNAs for binding to the ribosomal A site during protein translation. Previous studies have shown that eEF1A is methylated on several internal lysine residues to give mono-, di-, and tri-N-⑀-methyl-lysine derivatives. We confirm this finding but also detect methylation that is released as volatile methyl groups after base hydrolysis, characteristic of ester linkages. In cycloheximidetreated cells, methyl esterified eEF1A was detected largely in the ribosome and polysome fractions; little or no methylated protein was found in the soluble fraction. Because the base-labile, volatile [methyl-3 H]radioactivity of eEF1A could be released by trypsin treatment but not by carboxypeptidase Y or chymotrypsin treatment, we suggest that the methyl ester is present on the ␣-carboxyl group of its C-terminal lysine residue. From the results of pulse-chase experiments using radiolabeled intact yeast cells, we find that the N-methylated lysine residues of eEF1A are stable over 4 h, whereas the eEF1A carboxyl methyl ester has a half-life of less than 10 min. The rapid turnover of the methyl ester suggests that the methylation/demethylation of eEF1A at the Cterminal carboxyl group may represent a novel mode of regulation of the activity of this protein in yeast.Reversible covalent modification of proteins is a common mode of regulation in cell metabolism (1-3). A large number of protein phosphorylation and dephosphorylation reactions are involved in a variety of cell signaling and metabolic control reactions where specific kinases phosphorylate proteins using the ␥-phosphate group of ATP and dephosphorylation of these proteins occurs through the action of phosphatases (4). In a much smaller number of cases, methylation and demethylation reactions are also involved in cell signaling and, potentially, metabolic regulation (5). Methyltransferases use the methyl donor group on S-adenosylmethionine (AdoMet) 1 to methylate various substrates; methylesterases act to demethylate them.The yeast Saccharomyces cerevisiae contains the STE14 isoprenylcysteine methyltransferase that has been shown to methylate a wide range of proteins within the cell (6, 7). Its known substrates include the small G-proteins RAS1 and RAS2 and the secreted peptide a-factor (8 -10). The specific role of this methyltransferase is unknown, but it has been suggested that methylation of its products increases their hydrophobicity to help direct them to the membrane, decreases their rate of proteolytic degradation, and may modulate their protein-protein interactions involved in cell signaling (6).I...

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Section: Methylesterification Of Eef1a Is Rapidly Reversible In Intactmentioning

confidence: 99%

A Novel Post-translational Modification of Yeast Elongation Factor 1A

Zobel-Thropp¹,

Yang²,

Machado³

et al. 2000

Journal of Biological Chemistry

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The functional diversity of protein lysine methylation

Lanouette

Mongeon

Figeys

et al. 2014

Molecular Systems Biology

224

213

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Large-scale characterization of post-translational modifications (PTMs), such as phosphorylation, acetylation and ubiquitination, has highlighted their importance in the regulation of a myriad of signaling events. While high-throughput technologies have tremendously helped cataloguing the proteins modified by these PTMs, the identification of lysine-methylated proteins, a PTM involving the transfer of one, two or three methyl groups to the e-amine of a lysine side chain, has lagged behind. While the initial findings were focused on the methylation of histone proteins, several studies have recently identified novel non-histone lysinemethylated proteins. This review provides a compilation of all lysine methylation sites reported to date. We also present key examples showing the impact of lysine methylation and discuss the circuitries wired by this important PTM.

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