The reference OMIM entry for this protein is 312760

Ribosomal protein s4, x-linked; rps4x single-copy abundant mrna; scar
Cell cycle gene 2; ccg2

RPS4Y (470000), a Y-linked gene gene in the human, encodes ribosomal protein S4. A homologous locus on the human X chromosome, RPS4X, lies close to the X-inactivation center (314670) but fails to undergo X inactivation. Genetic mapping utilizing interspecific backcrosses and an intron probe derived from the mouse Rps4 gene demonstrated that Rps4 maps close to the Phka locus on the mouse X chromosome and in the vicinity of the X-inactivation center (Hamvas et al., 1991, 1992). Lafreniere et al. (1993) studied a 2.6-Mb contig of YACs that completely covered the region of the X-inactivation center and physically linked RPS4X, PHKA1, XIST, and DXS128E (an expressed DNA segment of unknown function), as well as a laminin receptor pseudogene (LAMRP4; see 150370). The order of genes was shown to be cen--RPS4X--PHKA1--XIST--DXS128E--tel. The transcriptional orientation of the RPS4X gene was cen--5-prime--3-prime--qter. Fisher et al. (1990) demonstrated that the RPS4Y and RPS4X proteins differ at 19 of 263 amino acids. Both genes are widely transcribed in human tissues, suggesting that the ribosomes of human males and females are structurally distinct. By transcription analysis, Fisher et al. (1990) found that 'unlike most genes on the X chromosome, RPS4X is not dosage compensated.' RPS4X was the first gene on the long arm of the X chromosome known to escape X inactivation. On the Y chromosome, RPS4Y maps to a 90-kb segment that has been implicated in Turner syndrome. XY gonadal dysgenesis patients with somatic features of the Turner syndrome have been found to have deletion of this portion of Yp. The Turner phenotype, or at least its extragonadal component, is probably the result of the presence of 1 rather than 2 copies of a gene or genes common to the X and Y chromosomes ('haploinsufficiency'). Kenmochi et al. (1998) confirmed the mapping assignment of the RPS4X gene to Xq. Zinn et al. (1991) found that in the mouse the Rps4 gene is indeed subject to X inactivation. This finding may explain why the phenotypic consequences of X monosomy are less severe in mice than in humans; the X0 mouse is a fertile female. Watanabe et al. (1993) demonstrated that the RPS4Y and RPS4X ribosomal proteins are interchangeable and provide an essential function: either protein rescued a mutant hamster cell line that was otherwise incapable of growth at modestly elevated temperatures. These findings are consistent with the hypothesis that RPS4 deficiency has a role in Turner syndrome. Geerkens et al. (1996) concluded that haploinsufficiency of RPS4X cannot be the cause of Turner syndrome because patients with 46,Xi(Xq) karyotype, i.e., isochromosome Xq, cannot be differentiated phenotypically from 45,X Turner syndrome patients but carry 3 copies of the RPS4X gene. In 4 patients with typical manifestations and a nonmosaic chromosome complement of isochromosome Xq, the authors found significantly increased RPS4X mRNA levels. Wiles et al. (1988) constructed a cDNA library from a mouse-human somatic cell hybrid containing as its only human contribution an X-6 translocation chromosome. From among clones that hybridized most strongly with DNA derived from the hybrid than with a 'mouse only' cell line, they found 1 devoid of repeats. This clone, called SCR10, identified a 1-kb mRNA transcribed from the human X chromosome and mapping to the region Xq13-q13.3 or Xq21.3-q22. It represented an abundantly and ubiquitously expressed gene. A full-length or nearly full-length clon ... More on the omim web site

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Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated

March 15, 2016: Protein entry updated
Automatic update: OMIM entry 312760 was added.