Parkinson's Disease Genes VPS35 and EIF4G1 Interact Genetically and Converge on alpha-Synuclein
NEURON
Authors: Dhungel, Nripesh; Eleuteri, Simona; Li, Ling-bo; Kramer, Nicholas J.; Chartron, Justin W.; Spencer, Brian; Kosberg, Kori; Fields, Jerel Adam; Stafa, Klodjan; Adame, Anthony; Lashuel, Hilal; Frydman, Judith; Shen, Kang; Masliah, Eliezer; Gitler, Aaron D.
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder. Functional interactions between some PD genes, like PINK1 and parkin, have been identified, but whether other ones interact remains elusive. Here we report an unexpected genetic interaction between two PD genes, VPS35 and EIF4G1. We provide evidence that EIF4G1 upregulation causes defects associated with protein misfolding. Expression of a sortilin protein rescues these defects, downstream of VPS35, suggesting a potential role for sortilins in PD. We also show interactions between VPS35, EIF4G1, and alpha-synuclein, a protein with a key role in PD. We extend our findings from yeast to an animal model and show that these interactions are conserved in neurons and in transgenic mice. Our studies reveal unexpected genetic and functional interactions between two seemingly unrelated PD genes and functionally connect them to alpha-synuclein pathobiology in yeast, worms, and mouse. Finally, we provide a resource of candidate PD genes for future interrogation.
Genome-Scale Networks Link Neurodegenerative Disease Genes to alpha-Synuclein through Specific Molecular Pathways
CELL SYSTEMS
Authors: Khurana, Vikram; Peng, Jian; Chung, Chee Yeun; Auluck, Pavan K.; Fanning, Saranna; Tardiff, Daniel F.; Bartels, Theresa; Koeva, Martina; Eichhorn, Stephen W.; Benyamini, Hadar; Lou, Yali; Nutter-Upham, Andy; Baru, Valeriya; Freyzon, Yelena; Tuncbag, Nurcan; Costanzo, Michael; San Luis, Bryan-Joseph; Schoendorf, David C.; Barrasa, M. Inmaculada; Ehsani, Sepehr; Sanjana, Neville; Zhong, Quan; Gasser, Thomas; Bartel, David P.; Vidal, Marc; Deleidi, Michela; Boone, Charles; Fraenkel, Ernest; Berger, Bonnie; Lindquist, Susan
Abstract
Numerous genes and molecular pathways are implicated in neurodegenerative proteinopathies, but their inter-relationships are poorly understood. We systematically mapped molecular pathways underlying the toxicity of alpha-synuclein (alpha-syn), a protein central to Parkinson's disease. Genome-wide screens in yeast identified 332 genes that impact alpha-syn toxicity. To "humanize'' this molecular network, we developed a computational method, Transpose Net. This integrates a Steiner prize-collecting approach with homology assignment through sequence, structure, and interaction topology. TransposeNet linked a-syn to multiple parkinsonism genes and druggable targets through perturbed protein trafficking and ER quality control as well as mRNA metabolism and translation. A calcium signaling hub linked these processes to perturbed mitochondrial quality control and function, metal ion transport, transcriptional regulation, and signal transduction. Parkinsonism gene interaction profiles spatially opposed in the network (ATP13A2/PARK9 and VPS35/PARK17) were highly distinct, and network relationships for specific genes (LRRK2/PARK8, ATXN2, and EIF4G1/PARK18) were confirmed in patient induced pluripotent stem cell (iPSC)-derived neurons. This cross-species platform connected diverse neurodegenerative genes to proteinopathy through specific mechanisms and may facilitate patient stratification for targeted therapy.