Abstract
Embryonic development is dependent upon the establishment of anterior-posterior (AP) axis, which is influenced by factors concentrated along the animal-vegetal axis of the egg. Factors localized in the vegetal pole activate Wnt signaling, leading to organization of the AP axis. One identified protein involved in the Wnt pathway is Disheveled (Dvl), which localizes at the vegetal pole of unfertilized eggs and early embryos where it activates the Wnt pathway. Casein kinase II (CK2) is a prominent protein kinase involved in development and is an important regulator of Wnt signaling. CK2 has been shown to interact with Dvl and mediate post-translational modification of Dvl by phosphorylation, but how CK2 phosphorylation of Dvl regulates its function within the Wnt pathway is not well known. The goal of this project is to characterize CK2 and understand how it interacts with Disheveled to regulate Wnt signaling during early development. For this project I conducted a phylogenetic analysis of the CK2 alpha and beta subunits to understand the structure of CK2 in sea urchins as compared to other metazoans. As an initial investigation of the functional roles of CK2 in early development, I attempted site-directed mutagenesis of a CK2 construct to create dominant-negative mutations of CK2. Using a construct made by a previous member of the lab containing a mutation for the CK2α ATP binding site, mRNA was injected into embryos, which when imaged demonstrated a range of phenotypes including partial anteriorization and a shortened gut. These results are preliminary data which aim to further the goal of understanding the mechanisms behind the role of CK2 in regulating development.