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Abstract
The bZIP gene superfamily is a family of transcription factors that have gone through multiple duplication events within bilaterians, specifically in vertebrates. This has led to multiple paralogs in each bZIP family while early diverging phyla have a single ortholog. These duplication events have motivated questions if the paralogs evolved to have new functions (neofunctionalization) or evolved to split the functions of the ancestor ortholog (subfunctionalization). The transcription factor, Nuclear Factor Erythroid 2 (NFE2) duplicated within vertebrates into at least four paralogs of Nrf1, Nrf2, Nrf3, and Nf-e2. Of these paralogs Nrf2 is well studied and has been characterized to upregulate antioxidant genes to alleviate stress from oxidizing molecules such as reactive oxygen species in the cell. The other three paralogs are involved proteasomal activity, redox homeostasis, and developmental processes. Knowing these paralogs have differing roles in vertebrates, NFE2 needs to be studied in an organism that has a single ortholog to decipher between neofunctionalization vs. subfunctionalization. Cnidarians are an insightful group to study NFE2 due to being sister group to bilaterians and possess a single ortholog. Using the sea anemone Nematostella vectensis as a model my research was focused to provide information on the ancestral function of NFE2 to compare with vertebrate paralogs and orthologs present in other invertebrates. In this study, database, phylogenetic, and molecular approaches were used to identify domains within and establish an interactome to begin characterization of function of Nematostella NFE2. Domain comparisons in NFE2 throughout animals showed that cnidarians have core domains important for DNA binding but lack some that elicit protein-protein interactions. In studying what proteins interact with Nematostella NFE2 I characterized an antibody specific to NFE2 to perform proteomic analysis. Of the resulting hundreds of characterized interactors, few were commonly characterized in vertebrates. From this proteomic analysis, cnidarian NFE2 may have a protein interactome unique in comparison to vertebrates, regulation mechanisms. Future research to characterize these proteins have been summarized to better understand the mechanisms of NFE2 regulation in animal evolution.