Summry—The molecular mechanism whereby protein kinase C (PKC) molecules transduce signals into the cell nucleus is unknown. In this study, we provide evidence thatDictyostelium discoideumcontains PKCδ‐like protein that is localized in the nucleus. TheDictyosteliumPKCδ‐like protein has an apparent molecular mass of 76 kDa. This protein is already highly expressed in vegetativeDictyosteliumcells. The expression level remained constant up to 12 h of development, and sharply decreased after 16 h. The PKCδ‐like protein is phosphorylatedin vivoin response to cAMP and phorbol ester stimulation. Immunofluorescent studies, as well as subcellular fractionation experiments, have indicated thatDictyosteliumPKCδ‐like protein is permanently located in the nucleus. Our results may indicate that PKCδ‐like protein inDictyosteliumfunctions as a link between cAMP and the tumor‐promoting phorbol esters, and events that take pl