title: Amino acid sequence of a novel calmodulin from Paramecium tetraurelia that contains dimethyllysine in the first domain.
abstract: A class of Paramecium behavioral mutants called pantophobiacs have a deficiency in calcium-dependent potassium efflux, and this deficiency can be corrected by the microinjection of wild-type Paramecium calmodulin (Hinrichsen, R. D., Burgess-Cassler, A., Soltvelt, B. C., Hennessey, T., and Kung, C. (1986) Science 232, 503-506). As a starting point in investigations of which features allow wild-type Paramecium calmodulin to fully restore this behavior while other calmodulins are inactive or poorly effective, we elucidated the amino acid sequence of the wild-type calmodulin. We utilized an approach that combined Edman chemistry with mass spectrometry. This approach resulted in the identification of a new post-translational modification in calmodulin: N epsilon,N epsilon-dimethyllysine at residue 13. This particular modification has not been described for calmodulins studied previously. The only other first-domain modification that has been described for any calmodulin is acetylation of the amino terminus (Watterson, D. M., Sharief, F., and Vanaman, T. C. (1980) J. Biol. Chem. 255, 962-975). These results along with analyses of pantophobiac calmodulin and calmodulin binding proteins will provide insight into calmodulin's role in a well-defined behavioral mutant.
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D002147:Calmodulin; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D003488:Cyanogen Bromide; D010450:Endopeptidases; D008239:Lysine / Q000031:analogs & derivatives*; D013058:Mass Spectrometry; D009154:Mutation; D010247:Paramecium / Q000032:analysis* / Q000235:genetics; D010446:Peptide Fragments; D011499:Protein Processing, Post-Translational; D012697:Serine Endopeptidases; D014357:Trypsin
chemical_list: D002147:Calmodulin; D010446:Peptide Fragments; C018926:epsilon N-dimethyllysine; D010450:Endopeptidases; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D014357:Trypsin; D008239:Lysine; D003488:Cyanogen Bromide