Addition and correction: the NF-kappa 3-like DNA binding activity observedin Dictyostelium nuclear extracts is due to the GBF transcription factor

We have previously reported that a NF-kappaB transduction pathway was likel y to be present in the cellular slime mold Dictyostelium discoideum. This c onclusion was based on several observations, including the detection of dev elopmentally regulated DNA binding proteins in Dictyostelium nuclear extrac ts that bound to bona fide kappaB sequences. We have now performed addition al experiments which demonstrate that the protein responsible for this NF-k appaB-like DNA binding activity is the Dictyostelium GBF (G box regulatory element binding factor) transcription factor. This result, along with the f act that no sequence with significant similarity to components of the mamma lian NF-kappaB pathway can be found in Dictyostelium genome, now almost ent irely sequenced, led us to reconsider our previous conclusion on the occurr ence of a NF-kappaB signal transduction pathway in Dictyostelium.