Phosphorylation and Ubiquitination Events in the Regulation of Gap Junction Protein Connexin 43

Abstract Connexin 43 (Cx43) accrual and removal from gap junctions is a complex progress regulated by specific phosphorylations, ubiquitinations and binding and release of regulatory proteins on the C- terminal tail of Cx43. In The?venin & Margraf et al., 2017, our lab showed that specific phosphorylations on the C-terminal tail of Cx43 occur before and after the binding and release of the scaffold protein Zona Occludens-1 (ZO-1). In Kells-Andrews & Margraf et al., 2018 we show that K63-poly-ubiquitination occurs on residues K264 and K303 of the Cx43 C-terminal tail. This undergraduate thesis summarizes the immunofluorescence imaging and quantification I have contributed to each of these papers, and additional work which further supports the ubiquitination of K264 and K303 on the Cx43 gap junction protein tail.