Interaction of Zebrafish FF1 Nuclear Receptors with SOX9a, WT1 and SHP

Previous work in our lab established that FF1b and FF1c are homologues of mammalian SF-1 and LRH in zebrafish. SF-1 was previously shown to interact with WT1 (Whim’s tumor 1) and SOX9 (SRY HMG box related gene 9) in regulation of the male sex determination pathway whereas LRH was shown to interact specifically with SHP (Small Heterodimer Partner). In this study, results of LexA yeast two-hybrid system in yeast suggest that FF1b and FF1c interact with WT1, SOX9, and SHP. The truncated mutants of FF1b up to AF2 core domain or heptad 9 domain lost their ability to interact with these proteins. Based on these results, we confirm the close relation of zebrafish FF1b and FF1c to mammalian SF-1 and LRH and the importance of Heptad 9 and AF2 domains in the interaction of FF1b with the three tested proteins. The yeast-two hybrid assay done in this project will be moved into a mammalian system for a better understanding of protein-protein interactions profile of zebrafish FF1s in comparison to that of SF-1 and LRH.