Recombinant Papio anubis 40S ribosomal protein S9 (RPS9)
Description
Ribosome Biogenesis and Localization
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RPS9 contains three nuclear localization regions, with its central domain acting as a potent nucleolar localization signal .
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It interacts with nucleolar chaperones like NPM1 (nucleophosmin), influencing nucleolar morphology and ribosome assembly .
Antiviral Defense Mechanisms
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In citrus plants, a homolog (ClRPS9-2) binds the coat protein of Citrus yellow vein clearing virus (CYVCV), reducing viral accumulation by ~50% and enhancing salicylic acid-mediated resistance .
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This suggests RPS9 may serve as a defense modulator in host-pathogen interactions .
Evolutionary and Genomic Studies
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The Papio anubis genome (Panubis1.0) contains 21,087 protein-coding genes, including RPS9, enabling comparative studies of ribosomal protein conservation across primates .
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Orthologs in humans (Homo sapiens) and yeast (Saccharomyces cerevisiae) show divergent splicing regulation, reflecting evolutionary adaptations in ribosome biogenesis .
Biochemical Handling and Stability
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Storage: Lyophilized forms remain stable for 12 months at -80°C; liquid forms last 6 months .
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Reconstitution: Requires gentle centrifugation and dilution in sterile water (0.1–1.0 mg/mL) with glycerol (5–50%) to prevent aggregation .
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Caution: Strictly for laboratory use—not approved for human administration .
Functional Genomics
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Facilitates studies on ribosomal protein autoregulation, including splice variants triggering nonsense-mediated decay (NMD) in Drosophila and humans .
Pathogen Interaction Models
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Transgenic lemon plants expressing ClRPS9-2 exhibit mild CYVCV symptoms, highlighting its potential in engineering disease-resistant crops .
Comparative Insights
| Organism | RPS9 Function | Key Reference |
|---|---|---|
| Papio anubis | Ribosome assembly, antiviral defense | |
| Homo sapiens | Colorectal cancer biomarker, rRNA binding | |
| Saccharomyces cerevisiae | Splicing-regulated paralogs (RPS9A/B) |
Future Directions
Current research gaps include elucidating RPS9’s role in primate-specific viral resistance and optimizing its use in structural biology. Advances in single-molecule sequencing and Hi-C scaffolding, as demonstrated in the Panubis1.0 genome, will enhance functional studies .
