Dictyostelium protein kinase C-delta-like protein is localized in the cell nucleus.
The molecular mechanism whereby protein kinase C (PKC) molecules transduce signals into the cell nucleus is unknown. In this study, we provide evidence that Dictyostelium discoideum contains PKC delta-like protein that is localized in the nucleus. The Dictyostelium PKC delta-like protein has an apparent molecular mass of 76 kDa. This protein is already highly expressed in vegetative Dictyostelium cells. The expression level remained constant up to 12 h of development, and sharply decreased after 16 h. The PKC delta-like protein is phosphorylated in vivo in response to cAMP and phorbol ester stimulation. Immunofluorescent studies, as well as subcellular fractionation experiments, have indicated that Dictyostelium PKC delta-like protein is permanently located in the nucleus. Our results may indicate that PKC delta-like protein in Dictyostelium functions as a link between cAMP and the tumor-promoting phorbol esters, and events that take place in the nucleus.
Department of Biochemistry, Hadassah Medical School, Hebrew University, Jerusalem, Israel.
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Wang
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Rubin
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D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000737:chemistry* / Q000201:enzymology; D000242:Cyclic AMP / Q000494:pharmacology; D004023:Dictyostelium / Q000737:chemistry / Q000201:enzymology* / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D005656:Fungal Proteins / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D007527:Isoenzymes / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D051745:Protein Kinase C-delta; D015398:Signal Transduction / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D005656:Fungal Proteins; D007527:Isoenzymes; D000242:Cyclic AMP; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D013755:Tetradecanoylphorbol Acetate