I. Gross et al., Dorsal-B, a splice variant of the Drosophila factor Dorsal, is a novel Rel/NF-kappa B transcriptional activator, GENE, 228(1-2), 1999, pp. 233-242
The Drosophila transcription factor Dorsal, a member of the Rel/NF-kappa B
family of proteins, plays a key role in the establishment of dorsoventral p
olarity in the early embryo and is also involved in the immune response. He
re, we present evidence that the primary transcript of dorsal can be altern
atively spliced, generating Dorsal-B, a new Rel/NF-kappa B family member. D
orsal and Dorsal-B are identical in the N-terminal region, which comprises
both a DNA-binding domain and a dimerization domain. However, Dorsal-B lack
s the nuclear localization signal located at the end of the Rel domain of D
orsal and is totally divergent in the C-terminal portion. Although Dorsal-B
by itself is not able to induce the expression of a kappa B-controlled Luc
iferase reporter gene, we demonstrate that its C-terminal portion has trans
activating properties. Analysis of the dorsal-B expression pattern indicate
s that the splicing is tissue-specific and excludes a putative role in earl
y embryogenesis. However, dorsal-B synthesis is enhanced upon septic injury
, and this challenge induces a nuclear accumulation of the protein in fat b
ody cells suggesting that it may be involved in the immune response. (C) 19
99 Elsevier Science B.V. All rights reserved.