Rapid Affinity-Based Fingerprinting of 14-3-3 Isoforms Using a Combinatorial Peptide Microarray

摘要

The 14-3-3 proteins are a family of acidic proteins (ca. 30 kDa) expressed in all eukaryotic cells. By binding as either homo- or heterodimers to a variety of phosphoserine-containing proteins, they regulate important cellular events including cell-cycle progression, DNA damage, apoptosis, protein trafficking, signal transduction, cytoskeletal rearrangements, metabolism, and transcriptional regulation. In humans, there are seven distinct but highly homologous 14-3-3 isoforms: β ε, η, γ, σ, τ, and ζ. Thus far, however, the only isoform directly linked to cancer has been 14-3-3σ, which is regulated by the major tumor suppressor gene, p53. Inactivation of 14-3-3σ is crucial in tumorigenesis. Consequently, there has been tremendous interest in the determination of the substrate specificity of 14-3-3-phosphopeptide binding as well as the structural basis of this interaction.