The Arabidopsis 14-3-3 Multigene Family

Abstract

The 14–3–3 proteins are ubiquitous eukaryotic proteins and are encoded by a gene family in many species. We examined the 14–3–3 gene family in Arabidopsis thaliana and found that it contains 10 members. Four new cDNAs, GF14[epsilon], GF14[kappa], GF14[mu], and GF14[nu], and two new genomic clones of GF14[phi] and GF14[upsilon] were isolated and characterized. Together with the six previously described 14–3–3 isoforms in Arabidopsis, they constitute a complete family of 10 distinct 14–3–3 proteins of 248 to 268 amino acids. Phylogenetic analysis revealed the presence of two ancient, distinct 14–3–3 gene classes in Arabidopsis and other plants. The [epsilon] forms diverged early from the other plant isoforms, and plant 14–3–3 genes displayed a different evolutionary course from that of mammals.