Ribosomal protein L5 (RPL5)

Ribosomal protein L5 (RPL5) is an essential structural constituent of the large 60S ribosomal subunit in eukaryotes[1][2][5]. RPL5 binds 5S rRNA to form the 5S ribonucleoprotein (RNP) complex, which is necessary for proper ribosome assembly and function—namely, facilitating protein synthesis within the cell[1][5][6]. Beyond its canonical role in translation and ribosome biogenesis, RPL5 exerts important extra-ribosomal functions. It can bind the oncoprotein MDM2 (alone or with RPL11), inhibit MDM2's ubiquitin ligase activity toward p53, and thereby regulate cell cycle arrest and apoptosis under nucleolar stress[1][3][5]. RPL5 also partners with RPL11 to promote c-Myc mRNA degradation, linking ribosome biogenesis to oncogene regulation and tumor suppression[1][4][5]. Mutations in RPL5 cause Diamond-Blackfan Anemia—a congenital bone marrow failure syndrome—and have been implicated in developmental abnormalities and potentially cancer[3][4][5]. No approved drugs currently directly target RPL5, but its unique regulatory roles in cellular stress responses and tumorigenesis are under investigation for future therapeutic applications.

Other names

Large ribosomal subunit protein uL1860S ribosomal protein L5RPL5uL18L5MSTP030PPP1R135Protein phosphatase 1 regulatory subunit 135

Indirect: Drugs that disrupt ribosome assembly or induce nucleolar stress may increase ribosome-free RPL5, activating its tumor suppressor functions through p53 stabilization