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.
Copyright © 2014, American Association for the Advancement of Science.
Publication types
- Research Support, Non-U.S. Gov't
MeSH terms
- Alternative Splicing
- Amyotrophic Lateral Sclerosis / genetics
- Amyotrophic Lateral Sclerosis / metabolism*
- Amyotrophic Lateral Sclerosis / pathology
- Astrocytes / metabolism*
- Astrocytes / pathology
- C9orf72 Protein
- Cell Death
- Cell Nucleolus / metabolism*
- Cells, Cultured
- Dipeptides / genetics
- Dipeptides / metabolism*
- Dipeptides / pharmacology
- Excitatory Amino Acid Transporter 2
- Frontotemporal Dementia / genetics
- Frontotemporal Dementia / metabolism*
- Frontotemporal Dementia / pathology
- Glutamate Plasma Membrane Transport Proteins / genetics
- Heterogeneous-Nuclear Ribonucleoprotein Group A-B / metabolism*
- Humans
- Hydrogel, Polyethylene Glycol Dimethacrylate
- Phosphorylation
- Protein Biosynthesis
- Protein Serine-Threonine Kinases / metabolism
- Protein Structure, Tertiary
- Protein-Tyrosine Kinases / metabolism
- Proteins / genetics*
- RNA, Antisense / antagonists & inhibitors
- RNA, Antisense / biosynthesis
- RNA, Messenger / antagonists & inhibitors
- RNA, Messenger / biosynthesis
- RNA, Ribosomal / antagonists & inhibitors
- RNA, Ribosomal / biosynthesis
- Repetitive Sequences, Amino Acid
- Transcription, Genetic
Substances
- C9orf72 Protein
- C9orf72 protein, human
- Dipeptides
- Excitatory Amino Acid Transporter 2
- Glutamate Plasma Membrane Transport Proteins
- Heterogeneous-Nuclear Ribonucleoprotein Group A-B
- Proteins
- RNA, Antisense
- RNA, Messenger
- RNA, Ribosomal
- SLC1A2 protein, human
- hnRNP A2
- Hydrogel, Polyethylene Glycol Dimethacrylate
- Clk dual-specificity kinases
- Protein-Tyrosine Kinases
- Protein Serine-Threonine Kinases