Arginine-rich C9ORF72 ALS proteins stall ribosomes in a manner distinct from a canonical ribosome-associated quality control substrate

Kriachkov, V; Ormsby, AR; Kusnadi, EP; McWilliam, HEG; Mintern, JD; Amarasinghe, SL; Ritchie, ME; Furic, L; Hatters, DM

Author(s): Kriachkov, V; Ormsby, AR; Kusnadi, EP; McWilliam, HEG; Mintern, JD; Amarasinghe, SL; Ritchie, ME; Furic, L; Hatters, DM;
Details: Publication Year 2023-01,Volume 299,Issue #1,Page 102774
Journal Title: Journal of Biological Chemistry
Publication Type: Research article
Abstract: Hexanucleotide expansion mutations in C9ORF72 are a frequent cause of amyotrophic lateral sclerosis. We previously reported that long arginine-rich dipeptide repeats (DPRs), mimicking abnormal proteins expressed from the hexanucleotide expansion, caused translation stalling when expressed in cell culture models. Whether this stalling provides a mechanism of pathogenicity remains to be determined. Here, we explored the molecular features of DPR-induced stalling and examined whether known mechanisms such as ribosome quality control (RQC) regulate translation elongation on sequences that encode arginine-rich DPRs. We demonstrate that arginine-rich DPRs lead to stalling in a length-dependent manner, with lengths longer than 40 repeats invoking severe translation arrest. Mutational screening of 40xGly-Xxx DPRs shows that stalling is most pronounced when Xxx is a charged amino acid (Arg, Lys, Glu, or Asp). Through a genome-wide knockout screen, we find that genes regulating stalling on polyadenosine mRNA coding for poly-Lys, a canonical RQC substrate, act differently in the case of arginine-rich DPRs. Indeed, these findings point to a limited scope for natural regulatory responses to resolve the arginine-rich DPR stalls, even though the stalls may be sensed, as evidenced by an upregulation of RQC gene expression. These findings therefore implicate arginine-rich DPR-mediated stalled ribosomes as a source of stress and toxicity and may be a crucial component in pathomechanisms.
Publisher: Elsevier
Keywords: Humans; *Amyotrophic Lateral Sclerosis/genetics/physiopathology; Arginine/metabolism; C9orf72 Protein/genetics/metabolism; Dipeptides/chemistry; Ribosomes/genetics/metabolism; Gene Knockout Techniques; Mutation; Up-Regulation; C9orf72 als; RNA-protein interaction; Rqc; arginine-rich dipeptide repeats; neurodegenerative disease; protein misfolding; ribosome function; ribosome stalling; translation
Department(s): Laboratory Research
PubMed ID: 36481270
Publisher's Version: https://doi.org/10.1016/j.jbc.2022.102774
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2023-05-30 07:27:56

Last Modified: 2024-07-09 06:24:24