Small ribosomal subunit protein eS1

Summary

RPS3A (Small ribosomal subunit protein eS1) is a 264-amino acid component of the small ribosomal subunit responsible for protein synthesis in the cell (UniProt: P61247). The protein participates in ribosome biogenesis as part of the small subunit processome, where it facilitates pre-rRNA folding, modification, and cleavage events coordinated with ribosomal assembly factors and the RNA exosome. It may also regulate the transcription factor DDIT3 during erythropoiesis.

RPS3A is widely expressed across tissues as a fundamental translation machinery component (UniProt: P61247). No additional disease associations are documented in UniProt beyond those flagged in this dataset.

In Alzheimer's Disease, RPS3A is significantly upregulated in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The protein showed a mean log2 fold-change of +0.19 across quantitative proteomics analysis of human brain subcellular fractions using TMT-labeled tandem mass spectrometry. This modest but consistent elevation may reflect altered translation capacity or ribosomal remodeling associated with AD pathology.