title: Poly-dipeptides encoded by the C9orf72 repeats bind nucleoli, impede RNA biogenesis, and kill cells.
abstract: Many RNA regulatory proteins controlling pre-messenger RNA splicing contain serine:arginine (SR) repeats. Here, we found that these SR domains bound hydrogel droplets composed of fibrous polymers of the low-complexity domain of heterogeneous ribonucleoprotein A2 (hnRNPA2). Hydrogel binding was reversed upon phosphorylation of the SR domain by CDC2-like kinases 1 and 2 (CLK1/2). Mutated variants of the SR domains changing serine to glycine (SR-to-GR variants) also bound to hnRNPA2 hydrogels but were not affected by CLK1/2. When expressed in mammalian cells, these variants bound nucleoli. The translation products of the sense and antisense transcripts of the expansion repeats associated with the C9orf72 gene altered in neurodegenerative disease encode GRn and PRn repeat polypeptides. Both peptides bound to hnRNPA2 hydrogels independent of CLK1/2 activity. When applied to cultured cells, both peptides entered cells, migrated to the nucleus, bound nucleoli, and poisoned RNA biogenesis, which caused cell death.
authors: Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Ilmin
authors: I
authors: Kwon
authors: Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Siheng
authors: S
authors: Xiang
authors: Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Masato
authors: M
authors: Kato
authors: Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Leeju
authors: L
authors: Wu
authors: Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Pano
authors: P
authors: Theodoropoulos
authors: Quantitative Biomedical Research Center, Department of Clinical Sciences, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Tao
authors: T
authors: Wang
authors: Quantitative Biomedical Research Center, Department of Clinical Sciences, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Jiwoong
authors: J
authors: Kim
authors: Quantitative Biomedical Research Center, Department of Clinical Sciences, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Jonghyun
authors: J
authors: Yun
authors: Quantitative Biomedical Research Center, Department of Clinical Sciences, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA.
authors: Yang
authors: Y
authors: Xie
authors: Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9152, USA. steven.mcknight@utsouthwestern.edu.
authors: Steven L
authors: SL
authors: McKnight
mesh_terms: D017398:Alternative Splicing; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D001253:Astrocytes / Q000378:metabolism* / Q000473:pathology; D000073885:C9orf72 Protein; D016923:Cell Death; D002466:Cell Nucleolus / Q000378:metabolism*; D002478:Cells, Cultured; D004151:Dipeptides / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D027342:Excitatory Amino Acid Transporter 2; D057180:Frontotemporal Dementia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D050491:Glutamate Plasma Membrane Transport Proteins / Q000235:genetics; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000378:metabolism*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D010766:Phosphorylation; D014176:Protein Biosynthesis; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011506:Proteins / Q000235:genetics*; D016372:RNA, Antisense / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012335:RNA, Ribosomal / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D020449:Repetitive Sequences, Amino Acid; D014158:Transcription, Genetic
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D004151:Dipeptides; D027342:Excitatory Amino Acid Transporter 2; D050491:Glutamate Plasma Membrane Transport Proteins; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D011506:Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; D012335:RNA, Ribosomal; C493397:SLC1A2 protein, human; C439768:hnRNP A2; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C066780:Clk dual-specificity kinases; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases