Pathway Summary for PUS3

Overview

PUS3 (Pseudouridine Synthase 3) is an RNA-modifying enzyme that catalyzes the isomerization of uridine to pseudouridine (Ψ) in tRNAs and other RNAs. This post-transcriptional modification is critical for RNA stability, structure, and function, particularly in tRNA-mediated translation.

Core Pathways

tRNA Modification Pathway

PUS3 modifies specific uridine residues in tRNAs:
- Position 38/39 in tRNA anticodon loop
- Enhances tRNA stability and function
- Improves codon-anticodon interactions
- Optimizes translation efficiency

Mitochondrial RNA Processing

PUS3 has dual localization and modifies:
- Mitochondrial tRNAs
- Potentially mitochondrial rRNAs
- Supports mitochondrial translation
- Maintains mitochondrial function

Pathway Diagram

graph TD A[tRNA Substrate] --> B[PUS3: Pseudouridine Synthase] B -->|U to Ψ| C[Modified tRNA] C --> D[Enhanced Translation] E[Mitochondrial tRNA] --> B B --> F[mt-tRNA Function] F --> G[Mitochondrial Translation] H[RNA Structure] --> I[Stabilization] C --> I style B fill:#f9f,stroke:#333,stroke-width:2px

Clinical Significance

Intellectual disability: PUS3 mutations cause syndromic ID
Mitochondrial dysfunction: Impaired mt-tRNA modification
Translation defects: Reduced protein synthesis efficiency