A Chlamydomonas homologue to the 14-3-3 proteins: cDNA and deduced amino acid sequence.

We have isolated and sequenced a 1464 bp cDNA from the unicellular green alga Chlamydomonas reinhardtii encoding an acidic polypeptide (259 aa) with considerable homologies to the 14-3-3 proteins of animals, yeasts and higher plants. Like the other members of this highly conserved protein kinase regulatory protein family, the deduced amino acid sequence of the Chlamydomonas 14-3-3 protein includes two putative phosphorylation sites within the N-terminal region (positions 62 and 67). Furthermore, an EF hand motif characteristic for Ca(2+)-binding sites is located within the C-terminal part of this polypeptide (positions 208-219). EF hand motifs are also present in the 14-3-3 proteins of some higher plants but not in those of animals and yeasts.