The Dictyostelium discoideum EB4 gene product and a truncated mutant form of the protein are localized in prespore vesicles but absent from mature spores.

Using polyclonal antibodies directed against two different parts of the predicted Dictyostelium prespore protein EB4-PSV, we have investigated the regulation and localization of its 58-kDa gene product in wild-type cells and a 31-kDa truncated form in the gene disruption transformant A3. In both strains, the protein is synthesized during aggregation and is found in the membrane fraction of prespore vesicles (PSV). In contrast to other PSV proteins, the EB4 gene product is not found in mature spores.