14-3-3ζ binds to the cytoplasmic domains of GPIbα and GPIbβ in yeast. Yeast were cotransformed with fusion proteins composed of GAL 4 modular domains hybridized to either GPIb, 14-3-3ζ, or control proteins. Data bars represent the mean ± SE of 5 separate experiments using analysis of 36 independent colonies and 3 spectrophotometric readings per colony at different concentrations. Five representative negative control transformations among the 8 performed are shown.