Reference articles on history, science, culture and more
Surprise meSurprise meSubscribe
Encyclopedia

40S ribosomal protein S25

Protein-coding gene in the species Homo sapiens

Wikipedia contributorsAdapted for Fathomly · View authors
1 min read
Source updated July 19, 2025
Image credit is listed at the end of this article.

40S ribosomal protein S25 (eS25) is a protein that in humans is encoded by the RPS25 gene.

Ribosomes are cellular macromolecules that catalyze protein synthesis across all kingdoms of life. The eukaryotic ribosome consists of a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and approximately 80 distinct proteins. The RPS25 gene encodes the eukaryote-specific ribosomal protein eS25 that is a component of the 40S subunit. As is typical for genes encoding ribosomal proteins, there are multiple processed pseudogenes of this gene dispersed through the genome.

01Interactions

Besides the interactions that position eS25 at its location in the E site region of the 40S ribosomal subunit, eS25 has been suggested to interact with other cellular proteins. One study has found that eS25 interacts with MDM2 as part of a regulatory feedback loop that stabilizes p53. Additionally, eS25 has been shown to interact with CDC5L.

02Function

As a ribosomal protein, eS25 likely plays a role in general protein synthesis; however, the RPS25 gene is non-essential for cellular viability in budding yeast and in select mammalian cell lines, implying that it is not essential for eukaryotic protein synthesis. Studies have implicated eS25 in the control of several specialized forms of translation, including that mediated by viral IRESs.

Watch videos about 40S ribosomal protein S25Explainers and documentaries on YouTube (opens in a new tab)

Sources and credits

This article is adapted from the Wikipedia article “40S ribosomal protein S25”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

Images, from Wikimedia Commons:

Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.

Continue exploring

Related topics

Translation (biology)

Translation is the process in biological cells in which proteins are produced using RNA molecules as templates. The generated protein is a sequence of amino acids determined by the sequence of nucleotides in the RNA. The nucleotides are considered three at a time.

Eukaryotic small ribosomal subunit (40S)

The eukaryotic small ribosomal subunit is the smaller subunit of the eukaryotic ribosome (80S), with the other major component being the large ribosomal subunit (60S). The "40S" and "60S" names originate from the convention that ribosomal particles are denoted according to their sedimentation coefficients in Svedberg units.

Internal ribosome entry site

An internal ribosome entry site, abbreviated IRES, is an RNA element that allows for translation initiation in a cap-independent manner, as part of the greater process of protein synthesis. Initiation of eukaryotic translation nearly always occurs at and is dependent on the 5' cap of mRNA molecules, where the translation initiation complex forms and ribosomes engage the mRNA. IRES elements, however, allow ribosomes to engage the mRNA and begin translation independently of the 5' cap.