40S ribosomal protein S21

40S ribosomal protein S21 is a protein that in humans is encoded by the RPS21 gene. This protein is a component of the 40S subunit of the ribosome, which is involved in the initiation of protein synthesis. Ribosomal proteins are highly conserved components of the ribosomal machinery and are essential for ribosome assembly and function. The 40S ribosomal protein S21 plays a critical role in the translation of mRNA into protein, a fundamental process in cell biology.

Function

The 40S ribosomal protein S21 is part of the small subunit of the ribosome and participates in the assembly and function of the ribosome, which is the cellular machinery responsible for protein synthesis. The ribosome translates the genetic information encoded in mRNA into a polypeptide chain, which then folds into a functional protein. The 40S subunit, in particular, is involved in the initiation phase of translation, binding to mRNA and the 60S ribosomal subunit to form an 80S initiation complex. The role of RPS21, like other ribosomal proteins, is to ensure the structural stability of the ribosome and to facilitate the accuracy of translation.

Gene

The RPS21 gene is located on chromosome 13 in humans. It encodes the 40S ribosomal protein S21, which is one of the proteins that make up the small subunit of the ribosome. The gene is expressed in various tissues, reflecting the ubiquitous need for protein synthesis in cells.

Clinical Significance

Alterations in the expression or function of ribosomal proteins, including RPS21, can lead to diseases known as ribosomopathies. These are a group of disorders arising from defects in ribosomal function, which can lead to a wide range of clinical manifestations, including developmental abnormalities and increased susceptibility to cancer. However, specific diseases directly associated with mutations in the RPS21 gene have not been well-characterized, reflecting the need for further research in this area.

Evolution

Ribosomal proteins, including 40S ribosomal protein S21, are highly conserved throughout evolution, underscoring their fundamental role in the biology of all living organisms. The conservation of these proteins across different species highlights the essential and universal nature of the protein synthesis machinery.

See Also

• Ribosome
• Protein synthesis
• Ribosomal proteins
• Ribosomopathies