Faculty Advisor

Saucedo, Leslie

Area of Study

Science and Mathematics

Publication Date

Summer 2012


The human body exhibits a spectacular collection of cells, integrated with seemingly infinite communication techniques and control mechanisms. Cancer’s disastrous influence on this complex system proves difficult to map. The shotgun clinical trial testing of human cancers has provided a feast of proteins suspected of encouraging cancerous cell behavior. One, Phosphatase of Regenerating Liver protein-1 (PRL-1), has been found to encourage cancerous growth while localizing in a variety of subcellular locations within metastasizing human tumor cells. However, PRL-1 has also been found to act as a tumor suppressor while localizing to the cell membrane in mammalian and insect models. In order to find what influence PRL-1’s subcellular location has on cellular behavior (tumor suppressing or enabling), PRL-1 and a modified version PRL-1NOCAAX were genetically overexpressed in Drosophila melanogaster (fruit fly) cells. PRL-1NoCAAX lacks the final four C-terminal amino acids (CAAX domain), disabling PRL-1’s prenylation for proper membrane association. Through fluorescent immunostaining, PRL-1 and PRL-1NoCAAX’s localization was microscopically observed at the cellular level. PRL-1 tightly associated apically to the membrane and functioned as a growth suppressor. PRL-1NoCAAX localization coated the cell membrane (apical to basal) and resulted in normal cell growth. When PRL-1 and PRL-1NoCAAX were coexpressed, polarized apical membrane localization returned, and surprisingly, normal cell growth ensued. This indicates that in a noncancerous environment, the CAAX domain is necessary for growth suppression.


University of Puget Sound