Purification of a 20 kDa phosphoprotein from epithelial cells and identification as a myosin light chain Phosphorylation induced by enteropathogenic Escherichia coli and phorbol ester

• Published in: FEBS letters Vol. 292; no. 1; pp. 121 - 127
• Main Authors: Manjarrez-Hernandez, H. Angel, Amess, Bob, Sellers, Lynda, Baldwin, Tom J., Knutton, Stuart, Williams, Peter H., Aitken, Alastair
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04.11.1991; Elsevier
• Subjects: Amino Acids - analysis; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Caco-2 cell; Cells, Cultured; Chromatography, Gel; deoxycholate; DOC; Electrophoresis, Polyacrylamide Gel; Enteropathogenic Escherichia coli; EPEC; Epithelial Cells; Epithelium - metabolism; Escherichia coli - metabolism; Fundamental and applied biological sciences. Psychology; HEp-2 cell; Humans; MHC; Miscellaneous; MLC; myosin heavy chain; Myosin light chain; Myosins - metabolism; Phorbol Esters - pharmacology; Phosphoproteins - isolation & purification; Phosphoproteins - metabolism; Phosphorylation; PKC; Precipitin Tests; Protein kinase C; Protein phosphorylation; Proteins; tetradecanoylphorbol-13-acetate; TPA; myosin heavy chain; Protein kinase C; TPA; MLC; deoxycholate; EPEC; MHC; PKC; Enteropathogenic Escherichia coli; Myosin light chain; HEp-2 cell; Caco-2 cell; DOC; Protein phosphorylation; tetradecanoylphorbol-13-acetate; Human; Immunoprecipitation reaction; Phosphorylation; Cell line; Purification; Escherichia coli; Myosin; light-Peptide chain; Bacteria; Enterobacteriaceae
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(91)80848-W

Previous studies on the mechanism of enteropathogenic Escherichia coli (EPEC) infection have revealed an increase in the phosphorylation state of a number of proteins in human laryngeal HEp-2 cells. The most prominent was an acidic phosphoprotein(s) of M r 20–21 kDa. The present study reports: (a) a simple method for purification of phosphorylated 20 kDa protein: (b) identification of the 20 kDa phosphoprotein as myosin light chain; and (c) that the phorbol ester. TPA, also increased the phosphorylation of the 20 kDa myosin light chain. In contrast to the effects of EPEC, TPA stimulation resulted in the dissociation of myosin from the cytoskeleton to the cytosol.