Endogenous Protein–Protein Interaction Network of the NPC Cholesterol Transporter 1 in the Cerebral Cortex

Abstract

NPC intracellular cholesterol transporter 1 (NPC1) is a multipass, transmembrane glycoprotein mostly recognized for its key role in facilitating cholesterol efflux. Mutations in the NPC1 gene result in Niemann-Pick disease, type C (NPC), a fatal, lysosomal storage disease. Due to the progressively expanding implications of NPC1-related disorders, we investigated endogenous NPC1 protein−protein interactions in the mouse cortex and human-derived iPSCs neuronal models of the disease through coimmunoprecipitation-coupled with LC-MS based proteomics. The current study investigated protein−protein interactions specific to the wild-type and the most prevalent NPC1 mutation (NPC1 I1061T ) while filtering out any protein interactor identified in the Npc1 −/− mouse model. Additionally, the results were matched across the two species to map the parallel interactome of wild-type and mutant NPC1 I1061T . Most of the identified wild-type NPC1 interactors were related to cytoskeleton organization, synaptic vesicle activity, and translation. We found many putative NPC1 interactors not previously reported, including two SCAR/WAVE complex proteins that regulate ARP 2/3 complex actin nucleation and multiple membrane proteins important for neuronal activity at synapse. Moreover, we identified proteins important in trafficking specific to wild-type and mutant NPC1 I1061T . Together, the findings are essential for a comprehensive understanding of NPC1 biological functions in addition to its classical role in sterol efflux.

Celebrating Women in Proteomics and Metabolomics

“…Led by Melanie Odenkirk from the group of Erin Baker comes a comprehensive study of the impact of apolipoprotein E disparities in patients with Alzheimer’s disease on the proteome and lipidome of distinct brain regions from post-mortem patients, suggesting mitochondrial dysfunction and cell proteostasis as tightly linked to pathology . The group of Stephanie Cologna contributed a study of the NPC intracellular cholesterol transporter 1 (NPC1) endogenous protein–protein interactions in the mouse cortex and human iPSCs neuronal models of disease . A characterization of human iPSCs and iPSC-derived neurons was also performed by Gwang Bin Lee in the group of Ling Hao via a multiomic integration of proteomics, lipidomics, and metabolomics analyses .…”