The Protein Kinase C Isoforms Leading to MAP-Kinase Activation in CHO Cells

• Published in: Biochemical and biophysical research communications Vol. 210; no. 3; pp. 639 - 647
• Main Authors: Yamaguchi, K., Ogita, K., Nakamura, S., Nishizuka, Y.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 25-05-1995
• Subjects: Amino Acid Sequence; Animals; Binding Sites; Calcium-Calmodulin-Dependent Protein Kinases - isolation & purification; Calcium-Calmodulin-Dependent Protein Kinases - metabolism; Cell Division - drug effects; CHO Cells; Chromatography; Chromatography, Gel; Chromatography, Ion Exchange; Cricetinae; Cytosol - enzymology; Durapatite; Enzyme Activation; Immunoblotting; Isoenzymes - biosynthesis; Isoenzymes - isolation & purification; Isoenzymes - metabolism; Kinetics; Molecular Sequence Data; Phorbol 12,13-Dibutyrate - metabolism; Phosphotyrosine; Protein Kinase C - biosynthesis; Protein Kinase C - isolation & purification; Protein Kinase C - metabolism; Tetradecanoylphorbol Acetate - pharmacology; Tyrosine - analogs & derivatives; Tyrosine - analysis
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1995.1708

Stimulation of CHO cells with phorbol ester caused transient activation of mitogen-activated protein kinase (MAP-kinases with 42 and 44 kDa). A similar treatment of CHO cells which overexpress a massive amount of the α- or δ-isoform of protein kinase C (PKC) resulted in the prolonged activation of MAP-kinase and eventually in the appearance of mostly dikaryotic, sometimes tetrakaryotic cells. The results suggest that the δ-isoform, as well as the α-isoform, has a potential to cause MAP kinase activation. Unusual activation of the PKC/MAP-kinase pathway, however, may lead to abnormal cytokinesis.