30 Apr 1999

The armadillo gene-so named because its mutated form in fruit flies produces a phenotype with short spiky hairs, reminiscent of those on the armadillo-codes for a protein that is a homologue of the human β-catenin. These proteins and other, structurally similar molecules, are sometimes referred to as the armadillo family of proteins. They have been shown to be active in signal transduction during apoptosis and embryogenesis (specifically Wnt/β-catenin-mediated processes) and in the maintenance of synapses and other intercellular junctions.

In the Journal of Neurochemistry, Peter St. George-Hyslop and his colleagues show specific interactions between presenilin 1 (PS1) and presenilin 2 (PS2) and three members of the armadillo protein family: β-catenin, p0071, and neural plakophilin-related armadillo protein (NPRAP), a novel, neuron-specific protein. They use yeast-two hybrid and coimmunoprecipitation methods to show that these interactions take place at the large cytoplasmic loop domains of PS1 and PS2. Their assays further identify an interaction between NPRAP and specific residues of PS1, leading the authors to suggest that this region "forms a functional armadillo protein binding site for the presenilins."—Hakon Heimer