PT  - JOURNAL ARTICLE
AU  - Duc T. Huynh
AU  - Jimin Hu
AU  - Jordan R. Schneider
AU  - Kalina N. Tsolova
AU  - Erik J. Soderblom
AU  - Abigail J. Watson
AU  - Jen-Tsan Chi
AU  - Chantell S. Evans
AU  - Michael Boyce
TI  - O-GlcNAcylation regulates neurofilament-light assembly and function and is perturbed by Charcot-Marie-Tooth disease mutations
AID  - 10.1101/2023.02.22.529563
DP  - 2023 Jan 01
TA  - bioRxiv
PG  - 2023.02.22.529563
4099  - http://biorxiv.org/content/early/2023/02/22/2023.02.22.529563.short
4100  - http://biorxiv.org/content/early/2023/02/22/2023.02.22.529563.full
AB  - The neurofilament (NF) cytoskeleton is critical for neuronal morphology and function. In particular, the neurofilament-light (NF-L) subunit is required for NF assembly in vivo and is mutated in subtypes of Charcot-Marie-Tooth (CMT) disease. NFs are highly dynamic, and the regulation of NF assembly state is incompletely understood. Here, we demonstrate that human NF-L is modified in a nutrient-sensitive manner by O-linked-β-N-acetylglucosamine (O-GlcNAc), a ubiquitous form of intracellular glycosylation. We identify five NF-L O-GlcNAc sites and show that they regulate NF assembly state. Interestingly, NF-L engages in O-GlcNAc-mediated protein-protein interactions with itself and with the NF component α-internexin, implying that O-GlcNAc is a general regulator of NF architecture. We further show that NF-L O-GlcNAcylation is required for normal organelle trafficking in primary neurons, underlining its functional significance. Finally, several CMT-causative NF-L mutants exhibit perturbed O-GlcNAc levels and resist the effects of O-GlcNAcylation on NF assembly state, indicating a potential link between dysregulated O-GlcNAcylation and pathological NF aggregation. Our results demonstrate that site-specific glycosylation regulates NF-L assembly and function, and aberrant NF O-GlcNAcylation may contribute to CMT and other neurodegenerative disorders.Competing Interest StatementThe authors have declared no competing interest.