2008 Eighth Annual Beckman Scholars Symposium
Saturday Poster Session - July 29, 2006

Lens development, like most other developmental processes, is critically regulated by various proteins and transcription factors that allow a smooth transition from an embryo to adult human. In particular, Prox1, an 83kDa transcription factor, is essential for the differentiation of lens epithelial cells to fiber cells and the formation of a functional lens. It is also involved in liver development and lymphangiogenesis and is highly expressed throughout the lymphatic system. A single transcription factor like Prox1 can only accommodate these diverse functions with the aid of specific protein-protein interactions. Such interacting protein partners were previously identified via yeast two-hybrid assay; in particular, the Prox1-sc35 interaction was chosen for further study. SC35, a member of SR splicing factor proteins, has a modular N-terminal RRM and C-terminal RS domain which could interact with the Homeo and/or Prospero domains of Prox1. We hypothesize that this interaction is important for the function and regulation of Prox1 as a transcription factor. To obtain any relevant morphological data, two mouse monoclonal Prox1 antibodies were first created and their species specificity determined by immunohistochemistry. Using these antibodies, we showed that Prox1 and sc35 are strictly colocalized in the nucleus of lens fiber cells where they may potentially interact in vivo. Currently new yeast constructs are being prepared to confirm our previous yeast two-hybrid results. Future work will map the physical region of Prox1-sc35 interactions and assess their functional significance.