Mechanistic studies into regulation of the copper chaperone CCS by phosphorylation

PROJECT SUMMARY Copper is an essential nutrient and vital for numerous cellular processes, including respiration, antioxidant defense, electron transfer, and protein quality control. However, its dysregulation can lead to diseases like cancer and neurodegeneration. Cancer cells exhibit increased copper needs to promote tumor growth, a process termed “cuproplasia.” In neurodegenerative diseases such as Parkinson's and ALS, copper mismanagement has been linked to the formation of toxic protein aggregates. One key protein in copper homeostasis is the metallochaperone CCS (Copper Chaperone for Superoxide Dismutase), which is responsible for delivering copper to other proteins, including SOD1 for redox regulation and MEK1/2 for cellular growth and proliferation. This proposal aims to investigate the regulation of CCS, focusing on its post-translational modification at serine 245, a phosphorylation site that may impact copper coordination and SOD1 activation. The aims of this proposal are to (1) explore how phosphorylation of serine 245 influences CCS copper-binding and transfer properties, (2) characterize the effects of this modification in cellular models, and (3) identify the kinases and phosphatases responsible for adding and removing this phosphorylation. The project employs a multidisciplinary approach, combining protein chemistry techniques like solid-phase peptide synthesis, biochemical assays, and cellular studies. These methods allow precise manipulation of CCS, enabling precise mechanistic studies of the effects of phosphorylation on copper binding. This work will provide insights into how copper homeostasis is regulated and open new avenues for therapeutic interventions targeting diseases associated with copper imbalance, such as ALS and cancer. This research will also offer training opportunities for junior researchers, especially undergraduate students, enhancing their expertise in both chemical and biological techniques while contributing to the broader understanding of metal ion homeostasis and its role in disease development.