Deciphering the Role of CTR1 Oligomeric States in Copper Homeostasis and Neuronal Differentiation

About This Grant

PROJECT SUMMARY This proposal aims to elucidate how the dynamic oligomeric transitions of Copper Transporter 1 (CTR1) couple copper (Cu) homeostasis with neuronal developmental pathways. Cu is an essential micronutrient for neuronal function, and a deficiency of Cu in early life can have devastating impacts on development. We recently discovered that CTR1 can reversibly transition between trimeric and monomeric states to regulate Cu uptake. Moreover, a CTR1 mutant that fails to undergo these de-oligomerization events impairs growth factor–activated signaling pathways. These findings challenge the conventional view of CTR1 as a stable trimeric transporter and suggest that Cu-induced allosteric changes in CTR1 oligomerization directly influence neuronal health and development. Our primary objectives are to determine the mechanisms driving CTR1’s oligomeric-state transitions and to clarify how these shifts impact CTR1’s function in Cu regulation and stem cell differentiation. Using innovative single-molecule assays, such as single-molecule localization microscopy and in-cell oligomer stoichiometry assays, we will visualize and quantify CTR1’s oligomeric states in situ. Human embryonic stem cell (hESC)-derived neurons will provide a physiologically relevant model for these studies. In addition, we will conduct comprehensive proteomic and biochemical analyses to uncover key protein interaction networks that modulate CTR1 trafficking and function. This proposal aims to address two main research directions: (1) identifying the triggers behind CTR1’s transition from trimeric to monomeric forms under conditions of excess Cu, and (2) exploring CTR1’s role in stem cell differentiation, with emphasis on its interactions with Laloo and SNT1 to regulate neuronal maturation. This multidisciplinary effort will be supported by collaborations with experts in neurobiology, membrane trafficking, Cu homeostasis, and stem cell research, thereby ensuring a robust and integrative approach. The insights gained will provide significant contributions to understanding CTR1’s role in Cu regulation and cell development, as well as elucidating its broader impact on neuronal health and disease. Additionally, the methodologies developed will have broad applicability for examining the dynamics of other membrane proteins. This project is innovative for several reasons: it introduces novel single-molecule assays for in situ studies, uses a more physiologically relevant hESC model, and addresses a critical gap in our understanding of allosteric regulation mediated by CTR1 in neurons. The insights gained from this research could have far-reaching implications in neurobiology and may inform strategies for treating Cu-related neurodegenerative diseases.