Acts in cell cycle and stress checkpoint signaling by sequestering signal transducers regulated by the checkpoints (By similarity). Required for the DNA damage checkpoint that ensures that DNA damage is repaired before mitosis is attempted (PubMed:8036497). Sequesters byr2 in the cytoplasm to prevent its translocation to the plasma membrane (PubMed:12242289). Interacts with rad24 (PubMed:12242289). Interacts with byr2 (PubMed:12242289). Belongs to the 14-3-3 family.