The 14-3-3 proteins are a highly conserved family of proteins involved in the regulation of cell survival. apoptosis. proliferation and checkpoint control (1-5). Biological regulation by 14-3-3 is mediated through phosphorylation-dependent protein-protein interactions (6). Two different phospho-Ser-containing motifs are found within nearly all known 14-3-3 binding proteins (7). Motif 1 (Arg/Lys and Ser at positions -3 and -2. phospho-Ser at position 0. and Pro at position +2) is found in critical regulatory proteins including Bad. cdc25c. FKHRL1. PKC and c-Raf (5.7). This antibody provides a powerful tool for the discovery and characterization of potential 14-3-3 binding proteins containing this motif and for high throughput drug discovery.