40S ribosomal protein S4, X isoform explained

40S ribosomal protein S4, X isoform is a protein that in humans is encoded by the RPS4X gene.^{[1] [2] [3]}

Ribosomes, organelles that catalyze protein synthesis, consist of a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and approximately 80 structurally distinct proteins. This gene encodes ribosomal protein S4, a component of the 40S subunit. Ribosomal protein S4 is the only ribosomal protein known to be encoded by more than one gene, namely this gene and ribosomal protein S4, Y-linked (RPS4Y). The 2 isoforms encoded by these genes are not identical, but are functionally equivalent. Ribosomal protein S4 belongs to the S4E family of ribosomal proteins. This gene is not subject to X-inactivation. It has been suggested that haploinsufficiency of the ribosomal protein S4 genes plays a role in Turner syndrome; however, this hypothesis is controversial. As is typical for genes encoding ribosomal proteins, there are multiple processed pseudogenes of this gene dispersed through the genome.^[3]

Further reading

• Wool IG, Chan YL, Glück A . Structure and evolution of mammalian ribosomal proteins . Biochem. Cell Biol. . 73 . 11–12 . 933–947 . 1996 . 8722009 . 10.1139/o95-101 .
• Fisher EM . Homologous ribosomal protein genes on the human X and Y chromosomes: escape from X inactivation and possible implications for Turner syndrome . Cell . 63 . 6 . 1205–1218 . 1991 . 2124517 . 10.1016/0092-8674(90)90416-C . vanc. Beer-Romero P . Brown LG . 3 . Ridley . Anne . McNeil . John A. . Lawrence . Jeanne Bentley . Willard . Huntington F. . Bieber . Frederick R. . Page . David C. . 16060228 .
• Wiles MV, Alexander CM, Goodfellow PN . Isolation of an abundantly expressed sequence from the human X chromosome by differential screening . Somat. Cell Mol. Genet. . 14 . 1 . 31–39 . 1988 . 2829364 . 10.1007/BF01535047 . 2698676 .
• Matoba R . The addition of 5'-coding information to a 3'-directed cDNA library improves analysis of gene expression . Gene . 146 . 2 . 199–207 . 1994 . 8076819 . 10.1016/0378-1119(94)90293-3 . vanc. Okubo K . Hori N . 3 . Atsushi . F . Kenichi . M .
• Maruyama K, Sugano S . Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides . Gene . 138 . 1–2 . 171–174 . 1994 . 8125298 . 10.1016/0378-1119(94)90802-8 .
• Watanabe M, Zinn AR, Page DC, Nishimoto T . Functional equivalence of human X- and Y-encoded isoforms of ribosomal protein S4 consistent with a role in Turner syndrome . Nat. Genet. . 4 . 3 . 268–271 . 1993 . 8358435 . 10.1038/ng0793-268 . 11495083 .
• Geerkens C, Just W, Held KR, Vogel W . Ullrich-Turner syndrome is not caused by haploinsufficiency of RPS4X . Hum. Genet. . 97 . 1 . 39–44 . 1996 . 8557258 . 10.1007/bf00218830. 9987276 .
• Vladimirov SN . Characterization of the human small-ribosomal-subunit proteins by N-terminal and internal sequencing, and mass spectrometry . Eur. J. Biochem. . 239 . 1 . 144–149 . 1996 . 8706699 . 10.1111/j.1432-1033.1996.0144u.x . vanc. Ivanov AV . Karpova GG . 3 . Musolyamov . Alekxander K. . Egorov . Tsezi A. . Thiede . Bernd . Wittmann-Liebold . Brigitte . Otto . Albrecht . free .
• Omoe K, Endo A . Relationship between the monosomy X phenotype and Y-linked ribosomal protein S4 (Rps4) in several species of mammals: a molecular evolutionary analysis of Rps4 homologs . Genomics . 31 . 1 . 44–50 . 1996 . 8808278 . 10.1006/geno.1996.0007 .
• Suzuki Y . Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library . Gene . 200 . 1–2 . 149–156 . 1997 . 9373149 . 10.1016/S0378-1119(97)00411-3 . vanc. Yoshitomo-Nakagawa K . Maruyama K . 3 . Suyama . A . Sugano . S .
• Kenmochi N . A map of 75 human ribosomal protein genes . Genome Res. . 8 . 5 . 509–23 . 1998 . 9582194 . 10.1101/gr.8.5.509 . vanc. Kawaguchi T . Rozen S . 3 . Davis . E . Goodman . N . Hudson . TJ . Tanaka . T . Page . DC. free .
• Uechi T, Tanaka T, Kenmochi N . A complete map of the human ribosomal protein genes: assignment of 80 genes to the cytogenetic map and implications for human disorders . Genomics . 72 . 3 . 223–230 . 2001 . 11401437 . 10.1006/geno.2000.6470 .
• Robinson RC . Crystal structure of Arp2/3 complex . Science . 294 . 5547 . 1679–1684 . 2001 . 11721045 . 10.1126/science.1066333 . vanc. Turbedsky K . Kaiser DA . 3 . Marchand . JB . Higgs . HN . Choe . S . Pollard . TD . 2001Sci...294.1679R . 18088124 .
• Andersen JS . Directed proteomic analysis of the human nucleolus . Curr. Biol. . 12 . 1 . 1–11 . 2002 . 11790298 . 10.1016/S0960-9822(01)00650-9 . vanc. Lyon CE . Fox AH . 3 . Leung . Anthony K.L. . Lam . Yun Wah . Steen . Hanno . Mann . Matthias . Lamond . Angus I. . free . 2002CBio...12....1A .
• Strausberg RL . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–16903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . vanc. Feingold EA . Grouse LH . 3 . Derge . JG . Klausner . RD . Collins . FS . Wagner . L . Shenmen . CM . Schuler . GD . 2002PNAS...9916899M . free .
• Agate RJ, Choe M, Arnold AP . Sex differences in structure and expression of the sex chromosome genes CHD1Z and CHD1W in zebra finches . Mol. Biol. Evol. . 21 . 2 . 384–396 . 2004 . 14660691 . 10.1093/molbev/msh027 . free .
• Ota T . Complete sequencing and characterization of 21,243 full-length human cDNAs . Nat. Genet. . 36 . 1 . 40–45 . 2004 . 14702039 . 10.1038/ng1285 . vanc. Suzuki Y . Nishikawa T . 3 . Otsuki . Tetsuji . Sugiyama . Tomoyasu . Irie . Ryotaro . Wakamatsu . Ai . Hayashi . Koji . Sato . Hiroyuki . free .

Notes and References

1. Watanabe M, Furuno N, Goebl M, Go M, Miyauchi K, Sekiguchi T, Basilico C, Nishimito T . Molecular cloning of the human gene, CCG2, that complements the BHK-derived temperature-sensitive cell cycle mutant tsBN63: identity of CCG2 with the human X chromosomal SCAR/RPS4X gene . J Cell Sci . 100 . 1. 35–43 . Apr 1992 . 10.1242/jcs.100.1.35 . 1795030 .
2. Zinn AR, Alagappan RK, Brown LG, Wool I, Page DC . Structure and function of ribosomal protein S4 genes on the human and mouse sex chromosomes . Mol Cell Biol . 14 . 4 . 2485–92 . Apr 1994 . 8139551 . 358616 . 10.1128/mcb.14.4.2485.
3. Web site: Entrez Gene: RPS4X ribosomal protein S4, X-linked.