SEQUENCE AND EXPRESSION ANALYSIS OF A XENOPUS-LAEVIS CDNA WHICH ENCODES A HOMOLOG OF MAMMALIAN 14-3-3-ZETA PROTEIN

We report the cloning and characterisation of a cDNA that encodes a no vel member of the Xenopus laevis 14-3-3 protein family. Sequence analy sis reveals that the cDNA-encoded protein shares 84% identity with the rat, human or sheep 14-3-3 zeta isoform, and between 66% and 77% iden tity with bovine, human or rat beta, bovine gamma, human tau, Drosophi la 14-3-3 and a previously isolated Xenopus member. The corresponding mRNA is present in all adult tissues examined with the highest levels in the brain. Although the gene is expressed throughout embryogenesis, higher levels of mRNA accumulate after gastrulation. Whole-mount in s itu hybridisation on tailbud stage embryo reveals strong expression of the gene in the head, optic vesicles, spinal cord and branchial arche s with weaker expression in the somites. In addition, expression along the notochord is observed at stage 45 (tadpole). This spatial and tem poral expression profile along with recent studies implicating the imp ortance of 14-3-3 proteins in the regulation of signal transduction pa thways argues for a key role of this isoform in embryonic development. (C) Elsevier Science B.V.