RPS4

RPS4 typically refers to ribosomal protein S4, a component of the small 40S ribosomal subunit in eukaryotes. It is involved in the assembly and function of the ribosome and contributes to the fidelity and efficiency of protein synthesis by interacting with ribosomal RNA and other ribosomal proteins during translation. The protein is highly conserved across eukaryotes and is expressed in most tissues.

In mammals, RPS4 is encoded by two paralogous genes: RPS4X on the X chromosome and RPS4Y on the Y chromosome. The X- and Y-linked copies can differ in sequence and expression patterns, which can influence dosage and regulation, particularly in tissues where X-inactivation or sex-specific expression plays a role. As with other ribosomal proteins, RPS4 is part of a gene family with broad evolutionary conservation.

Mutations or altered expression of ribosomal protein genes can contribute to ribosomopathies or affect cellular growth and stress responses. Specific disorders directly linked to RPS4 are less commonly described than for some other ribosomal proteins, but alterations in ribosomal components can impact hematopoietic development and general protein synthesis.

In plants, the acronym RPS4 also appears as the name of a disease-resistance gene in Arabidopsis thaliana. This plant RPS4 participates in effector-triggered immunity against certain bacterial pathogens and often operates in conjunction with other immune components to recognize pathogenic effectors and activate defense responses.

See also: RRS1–RPS4 resistance module (plant immunity)