- The presenilin protein family member SPE-4 localizes to an ER/Golgi derived organelle and is required for proper cytoplasmic partitioning during Caenorhabditis elegans spermatogenesis. Arduengo, P.M., Appleberry, O.K., Chuang, P., L'Hernault, S.W. J. Cell. Sci. (1998)