X11L2, a new member of the X11 protein family, interacts with Alzheimer's beta-amyloid precursor protein

We screened proteins for interaction with Alzheimer's beta-amyloid precurso r protein (APP) and cloned a new member of the X11 protein family, X11L2. T he PID/PTB element of X11L2 protein interacted with the intracellular domai n of APP by GST binding assay, and in vivo interaction was confirmed by coi mmunoprecipitation from cell extracts overexpressing APP and HA-tagged X11L 2. This gene encoded 575 amino acids and the deduced amino acid sequence wa s highly homologous to rat Mint3. Three protein-protein interaction domains , a PID/PTB and two PDZ elements, were conserved among the X11 protein fami ly, and the N-terminal region of X11L2 protein had several putative SH3 bin ding motifs, PXXP. Unlike other members of the X11 protein family, X11L2 mR NA was expressed in various tissues. (C) 1999 Academic Press.