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Updated: Jun 7, 2026

Pull-down of Calmodulin-binding Proteins
Published on: January 23, 2012
Calmodulin methyltransferase is an evolutionarily conserved enzyme that trimethylates Lys-115 in calmodulin
Roberta Magnani1, Lynnette M A Dirk, Raymond C Trievel
1Department of Horticulture, Plant Physiology/Biochemistry/Molecular Biology Program, University of Kentucky, Lexington, Kentucky 40546, USA.
Abstract:
Calmodulin (CaM) is a key mediator of calcium-dependent signalling and is subject to regulatory post-translational modifications, including trimethylation of Lys-115. In this paper, we identify a class I, non-SET domain protein methyltransferase, calmodulin-lysine N-methyltransferase (EC 2.1.1.60). A polypeptide chosen from a fraction enriched in calmodulin methyltransferase activity was trypsinized and analysed by tandem mass spectrometry. The amino-acid sequence obtained identified conserved, homologous proteins of unknown function across a wide range of species, thus implicating a broad role for lysine methylation in calcium-dependent signalling. Encoded by c2orf34, the human homologue is a component of two related multigene deletion syndromes in humans. Human, rat, frog, insect and plant homologues were cloned and Escherichia coli-recombinant proteins catalysed the formation of a trimethyllysyl residue at position 115 in CaM, as verified by product analyses and mass spectrometry.
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