Ribosome Quality Control (RQC) Project
Overview
Ribosome Quality Control (RQC) is a surveillance pathway that detects and resolves stalled or colliding ribosomes during translation. This prevents accumulation of aberrant proteins and maintains proteostasis. The field has seen major advances 2020+ with structural and mechanistic discoveries.
Model Species
Primary: Homo sapiens (human)
- Best characterized in human/mammalian systems
- Links to neurodegenerative disease (ALS, etc.)
Core Pathway Architecture
1. Collision Sensors
Detect ribosome collisions:
- ZNF598 - Ubiquitinates collided ribosomes (RPS10, RPS20)
- EDF1 - Collision sensor, recruits GIGYF2
- GIGYF2 - Recruits 4EHP to repress translation
2. Ribosome Splitting
Disassemble stalled ribosomes:
- PELO - Dom34 homolog, promotes subunit splitting
- HBS1L - GTPase, works with PELO
- ABCE1 - ATPase that physically separates subunits
3. RQC Complex
Handles 60S-nascent chain complexes:
- NEMF - Recruits LTN1, stabilizes nascent chain
- LTN1 - E3 ubiquitin ligase (Listerin)
- TCF25 - RQC complex component
- ANKZF1 - Vms1 homolog, releases stalled peptides
4. mRNA Decay
Targets problematic mRNAs:
- No-go decay pathway genes
5. Downstream Quality Control
- VCP/p97 - Extracts ubiquitinated substrates
- Proteasome - Degrades aberrant proteins
Candidate Genes (~15)
| Gene | UniProt | Function |
|---|---|---|
| ZNF598 | Q86UK7 | Collision sensor, E3 ligase |
| EDF1 | O60869 | Collision sensor |
| GIGYF2 | Q6Y7W6 | Translation repressor |
| PELO | Q9BRX2 | Ribosome rescue |
| HBS1L | Q9Y450 | GTPase for splitting |
| ABCE1 | P61221 | Ribosome splitting ATPase |
| NEMF | O00762 | RQC complex |
| LTN1 | O94822 | E3 ubiquitin ligase |
| TCF25 | Q9BQ70 | RQC complex |
| ANKZF1 | Q9H8Y5 | Peptide release |
| ASCC3 | Q8N3C0 | Helicase, collision resolution |
| ASCC2 | Q9H1I8 | ASCC complex |
| VCP | P55072 | AAA+ ATPase |
Key Recent Discoveries (2020+)
- EDF1 as collision sensor (2020)
- ASCC complex structure and function
- Structural basis of ribosome splitting
- Links to neurodegeneration
Disease Relevance
- ALS/neurodegeneration (C9orf72 repeat expansions cause ribosome stalling)
- NEMF mutations cause neurological disease
- Proteostasis disorders
Project Status
- [ ] Stub - needs gene folder setup