Evolution of signal multiplexing by 14-3-3-binding 2R-ohnologue protein families in the vertebrates. Issue 7 (July 2012)

• Record Type: Journal Article
• Authors: Tinti, Michele; Johnson, Catherine; Toth, Rachel; Ferrier, David E. K.; MacKintosh, Carol
• Is Part Of: Open biology. Volume 2:Issue 7(2012)
• Publication Date: 2012-07
• Subjects: Branchiostoma -- Ciona -- hereditary spastic paraplegia -- RAB3GAP1 -- RAB3GAP2; Biology -- Periodicals; 570
• DOI: 10.1098/rsob.120103
• Languages: English
• ISSNs: 2046-2441

Abstract

Abstract : 14-3-3 proteins regulate cellular responses to stimuli by docking onto pairs of phosphorylated residues on target proteins. The present study shows that the human 14-3-3-binding phosphoproteome is highly enriched in 2R-ohnologues, which are proteins in families of two to four members that were generated by two rounds of whole genome duplication at the origin of the vertebrates. We identify 2R-ohnologue families whose members share a 'lynchpin', defined as a 14-3-3-binding phosphosite that is conserved across members of a given family, and aligns with a Ser/Thr residue in pro-orthologues from the invertebrate chordates. For example, the human receptor expression enhancing protein (REEP) 1–4 family has the commonest type of lynchpin motif in current datasets, with a phosphorylatable serine in the –2 position relative to the 14-3-3-binding phosphosite. In contrast, the second 14-3-3-binding sites of REEPs 1–4 differ and are phosphorylated by different kinases, and hence the REEPs display different affinities for 14-3-3 dimers. We suggest a conceptual model for intracellular regulation involving protein families whose evolution into signal multiplexing systems was facilitated by 14-3-3 dimer binding to lynchpins, which gave freedom for other regulatory sites to evolve. While increased signalling complexity was needed for vertebrate life, these systems also generate vulnerability to genetic disorders.