Location: Cool and Cold Water Aquaculture ResearchTitle: Fbos, a novel oocyte-specific protein, interacts with proteins important for oocyte development in rainbow trout (Oncorhynchus mykiss) Author
Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/9/2010
Publication Date: 7/30/2010
Citation: Wang, L., Tripurani, S.K., Wanna, W., Rexroad III, C.E., Yao, J. 2010. Fbos, a novel oocyte-specific protein, interacts with proteins important for oocyte development in rainbow trout (Oncorhynchus mykiss) [abstract]. Society for the Study of Reproduction Annual Meeting. Paper No. 410. Interpretive Summary:
Technical Abstract: Oogenesis is characterized by a series of developmentally regulated events, which result in the matured oocyte that can give rise to a new organism after fertilization. Oocyte-specific genes play critical roles in oogenesis; however, the molecular details of oocyte-specific genes are poorly defined. Through analysis of expressed sequence tags (ESTs) from a rainbow trout oocyte cDNA library, we identified and characterized a novel oocyte-specific gene coding for an F-box protein (Fbos, F-box oocyte-specific). F-box proteins are components of ubiquitin-ligase complexes, which bind substrates for uiquitin-mediated proteolysis. F-box proteins have also been associated with cellular functions such as signal transduction and regulation of the cell cycle. To define the molecular mechanisms of Fbos-dependent biological processes during oogenesis in rainbow trout, we used Fbos as bait in a yeast two-hybrid screen system, along with a rainbow trout ovary cDNA library. More than 300 yeast colonies were able to grow on nutritional selective plates; 18 clones displayed strong LacZ activity as shown by colony lift filter assay for '-galactosidase activity. After verifying the interactions by reintroduction of the candidate prey plasmids into yeast reporter strain containing Fbos plasmid, 8 plasmids were rescued successfully and subjected to DNA sequence analysis. The sequencing data demonstrated that Fbos protein interacts with a number of proteins including histone H3.3, adenylate kinase 2, ribosomal protein L36, oocyte protease inhibitor 1, zona pellucida protein 2 (ZP2) and tissue inhibitor of metalloproteinase 2 (TIMP-2). All 5 proteins showed significant '-galactosidase activities at different levels compared to the control in a quantitative ß-galactosidase assay, indicating different binding affinities of these proteins with Fbos protein. Some of these proteins like ZP2 and TIMP-2 are known to play critical roles in oocyte development in various species. Our results suggest that through protein-protein interactions, the novel oocyte-specific F-box protein may play an important role in early oocyte development by regulating other critical proteins involved in oogenesis in rainbow trout.