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Antipeptide antibodies directed against the C‐terminus of protein kinase Cζ (PKCζ) react with a Ca 2+ ‐ and TPA‐sensitive PKC in HT‐29 human intestinal epithelial cells
Author(s) -
Batlle Eduard,
Fabre Myriam,
de Herreros Antonio García
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)00379-3
Subject(s) - protein kinase c , antibody , chemistry , microbiology and biotechnology , biochemistry , kinase , biology , immunology
We have studied the PKC isoforms present in HT‐29 M6 colon cancer cells, the differentiation of which to mucus‐secreting cells is blocked by TPA. In addition to a major 72 kDa band, a 77 kDa PKC isoform was recognized by two different antibodies raised against a C‐terminus‐specific peptide for the TPA‐insensitive isoform, PKCζ. By different criteria (association to the membrane, down‐regulation, PKC activity in immunoprecipitates) we conclude that, contrary to the 72 kDa band, the 77 kDa band corresponds to a Ca 2+ ‐ and TPA‐sensitive PKC. These results suggest that antipeptide antibodies directed against the C‐terminus of PKCζ react in human cells with a member of the conventional PKC subfamily besides PKCζ. Therefore, the data indicating that PKCζ is sensitive to different agents in various cell lines should be carefully re‐evaluated.