Mitochondrial ribosomal protein L23 explained

39S ribosomal protein L23, mitochondrial is a protein that in humans is encoded by the MRPL23 gene.^{[1] [2]}

Function

Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a 39S subunit protein. The gene is biallelically expressed, despite its location within a region of imprinted genes on chromosome 11.

Further reading

• Sun XX, Dai MS, Lu H . 5-fluorouracil activation of p53 involves an MDM2-ribosomal protein interaction . J. Biol. Chem. . 282 . 11 . 8052–9 . 2007 . 17242401 . 10.1074/jbc.M610621200 . free .
• Zhang Z, Gerstein M . Identification and characterization of over 100 mitochondrial ribosomal protein pseudogenes in the human genome . Genomics . 81 . 5 . 468–80 . 2003 . 12706105 . 10.1016/S0888-7543(03)00004-1 .
• O'Brien TW . Evolution of a protein-rich mitochondrial ribosome: implications for human genetic disease . Gene . 286 . 1 . 73–9 . 2002 . 11943462 . 10.1016/S0378-1119(01)00808-3 .
• Kenmochi N, Suzuki T, Uechi T, Magoori M, Kuniba M, Higa S, Watanabe K, Tanaka T . The human mitochondrial ribosomal protein genes: mapping of 54 genes to the chromosomes and implications for human disorders . Genomics . 77 . 1–2 . 65–70 . 2001 . 11543634 . 10.1006/geno.2001.6622 .
• Suzuki T, Terasaki M, Takemoto-Hori C, Hanada T, Ueda T, Wada A, Watanabe K . Structural compensation for the deficit of rRNA with proteins in the mammalian mitochondrial ribosome. Systematic analysis of protein components of the large ribosomal subunit from mammalian mitochondria . J. Biol. Chem. . 276 . 24 . 21724–36 . 2001 . 11279069 . 10.1074/jbc.M100432200 . free .

Notes and References

1. Tsang P, Gilles F, Yuan L, Kuo YH, Lupu F, Samara G, Moosikasuwan J, Goye A, Zelenetz AD, Selleri L . A novel L23-related gene 40 kb downstream of the imprinted H19 gene is biallelically expressed in mid-fetal and adult human tissues . Hum Mol Genet . 4 . 9 . 1499–507 . Feb 1996 . 8541832 . 10.1093/hmg/4.9.1499 .
2. Web site: Entrez Gene: MRPL23 mitochondrial ribosomal protein L23.