Small ribosomal subunit protein uS5

Small ribosomal subunit protein uS5 (RPS2) is a core component of the ribosome's 40S small subunit, essential for protein synthesis. It participates in mRNA binding and aminoacyl-tRNA selection, and is involved in ribosomal assembly and nucleolar processing of pre-18S ribosomal RNA (UniProt: P15880). The protein functions as part of the larger ribosomal machinery that catalyzes peptide bond formation and coordinates nascent polypeptide processing.

RPS2 is ubiquitously expressed as a fundamental translation factor without curated disease associations in UniProt. However, the protein's central role in protein synthesis implicates it in cellular processes dependent on translational capacity and efficiency.

In Alzheimer's Disease, RPS2 shows reduced abundance in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics), with a mean log2 fold-change of −0.26 across the examined subcellular fraction. This downregulation suggests potential compromise in ribosomal function or translational capacity in the AD brain, which may contribute to protein homeostasis imbalance associated with neurodegeneration.