Fig. 1.

Generation of EBP50-deficient mice. (A) Targeted disruption of the EBP50 locus. A fragment of the wild-type locus (Top) containing the first and last two exons (solid boxes) and the polyadenylation signal (pA) of EBP50 is shown. The targeting construct (Middle) consisting of a 4.0-kb 5′ genomic fragment, a 1.8-kb 3′ genomic fragment, and the neo^R gene without the polyadenylation signal (NeoΔpA) replaces a 16-kb genomic fragment containing exons 1–4 of the EBP50 gene in the targeted mutated locus (Bottom). The solid arrowheads flanking the neo^R gene represent LoxP sites. The positions of the Southern blot probe (hatched boxes), EcoRI sites (E), and the EcoRI wild-type and mutated genomic fragments (double-pointed arrows) are shown. The Southern analysis is shown beneath. (B) Schematic representation of the EBP50 domain structure. The two PDZ domains (1 and 2) and the C-terminal ERM-binding (EB) region are shown with the respective boundaries in amino acids. Solid arrowheads indicate EBP50 mRNA splice sites that delimit EBP50's six exons. Some known interacting proteins for the various domains are listed in italics above each domain. The dimerization with itself or NHERF2 and the interaction with NHE3 most likely extend through both PDZ domains. (C) Western blot analysis of EBP50 from whole organs homogenized in TNN buffer. The organs were collected from two mice per each genotype.