Expanded GGGGCC (G4C2) hexanucleotide repeats in the C9orf72 gene were recently identified as the most common genetic cause of Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD), two neurodegenerative disorders with genetic and pathological overlap. Repeat-RNA-toxicity mediated by sequestering key RNA binding proteins is thought to play key roles in c9ALS/FTD pathogenesis. However, which RNA binding protein(s) might be sequestered by long G4C2 repeat RNAs is still unknown. We propose to identify RNA-protein interactions in c9ALS/FTD using disease-relevant repeat lengths and cell models, and by comparison to interacting-proteins of (TG3C2) repeats, a similar repeat expansion that leads to a clinically disparate disease Spinocerebellar Ataxia type 36 (SCA36). The identified RNA binding protein(s) by the G4C2 repeats will be further validated in c9ALS/FTD patient postmortem brain samples and its functions will be studied in iPS-derived motor neurons and in mice. Results from this proposal will provide new insight into the cellular cascades that cause neurodegeneration in c9ALS/FTD.

Public Health Relevance

Hexanucleotide GGGGCC repeat expansion in the C9ORF72 gene is the most frequent cause of two neurodegenerative diseases, Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD). One potential pathogenic mechanism is mediated through repeat containing RNAs that form nuclear RNA foci. This project will identify the RNA binding proteins sequestered and may lead to identification of new therapeutic targets.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21NS114908-02
Application #
10019613
Study Section
Cellular and Molecular Biology of Neurodegeneration Study Section (CMND)
Program Officer
Gubitz, Amelie
Project Start
2019-09-18
Project End
2021-08-31
Budget Start
2020-09-01
Budget End
2021-08-31
Support Year
2
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Emory University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322