Proteomic analysis of 14-3-3 zeta binding proteins in the mouse hippocampus.

14-3-3 proteins are ubiquitous molecular chaperones with important roles in brain development and neuronal function. Altered expression of 14-3-3 proteins has been reported in several neurologic and neurodegenerative disorders and identifying 14-3-3 binding proteins may provide important insights into the physiologic and pathophysiologic roles of these proteins. Particular interest has emerged on 14-3-3 zeta (ζ) in the setting of neuronal injury because reducing 14-3-3ζ levels triggers an endoplasmic reticulum stress-like response in neurons and increases vulnerability to excitotoxicity. Here we examined the subcellular distribution of 14-3-3ζ in the mouse hippocampus. We then used recombinant His-tagged 14-3-3ζ to pull-down interacting proteins from the mouse hippocampus followed by identification by liquid chromatography-mass spectrometry. 14-3-3ζ protein was present in the cytoplasm, microsomal compartment, nucleus and mitochondrial fractions of the mouse hippocampus. Recombinant 14-3-3ζ eluted 13 known 14-3-3 binding partners, including three other 14-3-3 isoforms, and 16 other proteins which have not previously been reported to bind 14-3-3ζ. The present study identifies potentially novel 14-3-3ζ binding proteins and contributes to defining the 14-3-3ζ interactome in the mouse brain.