Proteomics, Post-Translational Modifications, & Protein Interaction Studies of Neurodegenerative Diseases

Mass spectrometry (MS) is a powerful analytical technique that can be used to identify changes in biological systems to widen our knowledge of protein functions, signaling pathways, and disease mechanisms. The development of electrospray ionization (ESI) has allowed the coupling of liquid chromatography (LC) with MS, enabling a robust analysis of biomolecules such as proteins, lipids, metabolites, antibodies, and nucleic acids. However, as biological systems are complex, LC-MS sample preparation workflows face multiple challenges. Examples include the extraction of membrane proteins and the detection of post-translational modifications. In this dissertation, LC-MS was used to i) identify new phosphosites on the protein TRPM7, ii) investigate the NPC1 interactome in mouse brain tissues, iii) analyze changes in proteins and signaling in a murine model of Niemann-Pick disease, type C (NPC), and iv) analyze the palmitoylation state of Gsα after antidepressant treatments. The knowledge provided by mass spectrometry can be further explored using microscopy and other biochemical techniques. From the studies, multiple novel phosphosites and probable interactors of NPC1 protein were identified in different brain regions. In addition, CaMKII and NR2B were suggested to play a role in the degeneration of neurons in NPC.