Fowler, Stephanie L2013-11-072013-11-0720092009Source: Masters Abstracts International, Volume: 48-06, page: 3538.http://hdl.handle.net/10393/28449http://dx.doi.org/10.20381/ruor-19269Connexin proteins are the structural components of gap junctions and hemichannels, and are dynamically regulated in neural progenitor cells (NPCs) over the course of neurogenesis. While the classical role of connexins is to mediate juxtacrine and paracrine signalling through plasma membrane channels, new evidence suggests that a plethora of channel-independent signalling roles are initiated by protein-protein interactions. In this thesis, I provide evidence for a novel Connexin 32 (Cx32)-interactome (i.e., interacting proteins that may not be associated with plasma membrane channels) that can be subsequently tested for impact on NPC fate. Following rigorous testing of various Cx32 protein detection strategies designed to overcome a problem with brain-specific antibody cross-reactivity, I developed a new method to affinity-purify endogenous Cx32 combining sucrose gradient fractionation and immunoprecipitation (IP). Combined with high performance liquid chromatography and tandem mass spectrometry, nineteen Cx32 binding partners were identified. Surprisingly, many of these interacting proteins were predicted to localize to the mitochondrion. Interaction of Cx32 with slderoflexln-1 (SFXN-1), a putative mitochondrial protein, at both plasma and mitochondrial membranes was further verified by co-IP. Together these results suggest that a small pool of Cx32 localizes to the mitochondrion and provides the first proof of principle that Cx32 interacts with mitochondrial protein complexes at both plasma membrane and mitochondrial locations.214 p.enBiology, Neuroscience.Thesis