Determining whether ROK and Rac mediate PRL-1 Function in Drosophila melanogastor

Rosemary Dinkins, University of Puget Sound


Phosphatases of Regenerating Liver (PRL) are proteins that have been linked to the metastatic events of cell migration, invasiveness, and proliferation when PRL is overexpressed. This experiment explores the normal function of PRL-1 in Drosophila melanogaster (fruit fly) as it relates to a possible metastasis promoting PRL-1 pathway involving ROK and Rac. Rac is a member of the protein family Rho GTPase and plays a significant role in cell migration. ROK, or Rho-associated kinase, is a known downstream effector of Rho-GTPases and is necessary for the regulation of cell motility. The migrational functions of ROK and Rac, as well as evidence suggesting their involvement in a PRL-1 pathway, suggests that at least one metastasis promoting pathway PRL-1 uses involves ROK and Rac. The relationships PRL-1 has with ROK and Rac were explored by observing how the independent overexpression or reduced expression of both ROK and Rac affect the PRL-1 overexpression wing phenotype in fruit flies. It was found that the PRL-1 overexpression phenotype causes fewer cells to be present on the dorsal versus ventral side of the fruit fly wing in comparison to the control fly wings. There were no significant results when ROK expression was manipulated in conjunction with PRL-1 overexpression. However, when flies overexpressing PRL-1 also had a reduced expression of Rac, the PRL-1 overexpression phenotype was reduced such that the ventral versus dorsal wing cell difference was not significantly different from the control wings; the PRL-1/Rac results suggest that Rac is a necessary component of PRL-1 expression.