Mouse Tspan-5, a member of the tetraspanin superfamily, is highly expressed in brain cortical structures.

Using a subtractive hybridization method for the identification of genes related to the development of the murine cerebral cortex, we cloned a mouse homologue of a human tetraspanin family member, Tspan-5. We have isolated a 3.1 Kb cDNA fragment containing the entire coding region. Analysis of the cDNA nucleotide sequence revealed that mouse Tspan-5 shares 98% amino acid sequence identity with its human homologue. The predicted length of the mouse protein is 268 amino acids, with four putative hydrophobic domains with N- and C-intracellular tails, and two extracellular domains. Northern blot analysis of adult mouse tissues showed a single transcript, which is preferentially expressed in the brain. In situ hybridization showed prominent expression of Tspan-5 in the neocortex, the hippocampus, amygdala and in Purkinje cells in the cerebellum. The pattern of expression of Tspan-5 in the mouse brain suggests a role for the tetraspanins in the maintenance of adult brain function.