Insights into the C-terminal Peptide Binding Specificity of the PDZ Domain of Neuronal Nitric-oxide Synthase: CHARACTERIZATION OF THE INTERACTION WITH THE TIGHT JUNCTION PROTEIN CLAUDIN-3.

Neuronal nitric-oxide synthase, unlike its endothelial and inducible counterparts, displays a PDZ (PSD-95/Dlg/ZO-1) domain located at its N terminus involved in subcellular targeting. The C termini of various cellular proteins insert within the binding groove of this PDZ domain and determine the subcellular distribution of neuronal NOS (nNOS). The molecular mechanisms underlying these interactions are poorly understood because the PDZ domain of nNOS can apparently exhibit class I, class II, and class III binding specificity.