HGNC Approved Gene Symbol: RPS4Y1
Cytogenetic location: Yp11.2 Genomic coordinates (GRCh38): Y:2,841,602-2,867,268 (from NCBI)
Fisher et al. (1990) isolated 2 genes on the human sex chromosomes, one on Y and the other on X, that encode isoforms of ribosomal protein S4. These proteins, RPS4Y and RPS4X (312760), 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.
RPS4Y, 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)). 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.
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 RPS4Y gene to Yp.
Fisher, E. M. C., Beer-Romero, P., Brown, L. G., Ridley, A., McNeil, J. A., Lawrence, J. B., Willard, H. F., Bieber, F. R., Page, D. C. Homologous ribosomal protein genes on the human X and Y chromosomes: escape from X inactivation and possible implications for Turner syndrome. Cell 63: 1205-1218, 1990. [PubMed: 2124517] [Full Text: https://doi.org/10.1016/0092-8674(90)90416-c]
Hamvas, R. M., Brown, S. D., Keer, J. T., Fisher, E. M., Romero, P., Zinn, A., Page, D. The mapping of the locus Rps4 to the X-inactivation region in the mouse. (Abstract) Cytogenet. Cell Genet. 58: 2065-2066, 1991.
Hamvas, R. M. J., Zinn, A., Keer, J. T., Fisher, E. M. C., Beer-Romero, P., Brown, S. D. M., Page, D. C. Rps4 maps near the inactivation center on the mouse X chromosome. Genomics 12: 363-367, 1992. [PubMed: 1740345] [Full Text: https://doi.org/10.1016/0888-7543(92)90386-7]
Kenmochi, N., Kawaguchi, T., Rozen, S., Davis, E., Goodman, N., Hudson, T. J., Tanaka, T., Page, D. C. A map of 75 human ribosomal protein genes. Genome Res. 8: 509-523, 1998. [PubMed: 9582194] [Full Text: https://doi.org/10.1101/gr.8.5.509]
Zinn, A. R., Bressler, S. L., Beer-Romero, P., Adler, D. A., Chapman, V. M., Page, D. C., Disteche, C. M. Inactivation of the Rps4 gene on the mouse X chromosome. Genomics 11: 1097-1101, 1991. Note: Erratum: Genomics 13: 915 only, 1992. [PubMed: 1783379] [Full Text: https://doi.org/10.1016/0888-7543(91)90037-f]