Small ribosomal subunit protein eS6

RPS6 (small ribosomal subunit protein eS6) is a component of the 40S small ribosomal subunit that plays a critical role in controlling cell growth and proliferation by regulating the selective translation of specific mRNA classes (UniProt: P62753). The protein is part of the small subunit processome, functioning during ribosomal assembly in the nucleolus where it participates in pre-rRNA processing, modification, and quality control mechanisms.

RPS6 is implicated in Alzheimer's Disease pathology based on proteomics profiling. Analysis of post-mortem AD brain tissue compared to age-matched controls using TMT-labeled quantitative proteomics across four subcellular fractions (P2, P3, S2, S3) revealed an ambiguous direction of change, with a mean log2 fold-change of 0.13 (Chaparral AD proteomics). The ambiguous direction indicates that RPS6 abundance changes inconsistently across subcellular fractions, suggesting compartment-specific dysregulation of ribosomal protein homeostasis in AD pathogenesis rather than a uniform increase or decrease.