title: 14-3-3 phosphoprotein interaction networks - does isoform diversity present functional interaction specification?
abstract: The 14-3-3 proteins have emerged as major phosphoprotein interaction proteins and thereby constitute a key node in the Arabidopsis Interactome Map, a node through which a large number of important signals pass. Throughout their history of discovery and description, the 14-3-3s have been described as protein families and there has been some evidence that the different 14-3-3 family members within any organism might carry isoform-specific functions. However, there has also been evidence for redundancy of 14-3-3 function, suggesting that the perceived 14-3-3 diversity may be the accumulation of neutral mutations over evolutionary time and as some 14-3-3 genes develop tissue or organ-specific expression. This situation has led to a currently unresolved question - does 14-3-3 isoform sequence diversity indicate functional diversity at the biochemical or cellular level? We discuss here some of the key observations on both sides of the resulting debate, and present a set of contrastable observations to address the theory functional diversity does exist among 14-3-3 isoforms. The resulting model suggests strongly that there are indeed functional specificities in the 14-3-3s of Arabidopsis. The model further suggests that 14-3-3 diversity and specificity should enter into the discussion of 14-3-3 roles in signal transduction and be directly approached in 14-3-3 experimentation. It is hoped that future studies involving 14-3-3s will continue to address specificity in experimental design and analysis.
authors.affiliation: Program in Plant Molecular and Cellular Biology, Horticultural Science Department, University of Florida Gainesville, FL, USA.
authors.forename: Anna-Lisa
authors.initials: AL
authors.lastname: Paul
authors.forename: Fiona C
authors.initials: FC
authors.lastname: Denison
authors.forename: Eric R
authors.initials: ER
authors.lastname: Schultz
authors.forename: Agata K
authors.initials: AK
authors.lastname: Zupanska
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ferl