We have been studying the genetics and biochemistry of the steroid sulfatase (STS) system. This microsomal enzyme is capable of desulfating a range of 3Beta-hydroxysteroid sulfates. It plays a major role in the hydrolysis of sulfated precursors for estrogen biosynthesis during pregnancy and is involved in the regulation of sulfated steroid metabolism in later life as well. Patients genetically deficient in STS have been frequently identified (about 1 in 6,000 males). They are the products of pregnancies in which estrogen production is deficient by virtue of absence of placental sulfatase activity. Due to the diminished estrogen levels, pregnancies are frequently prolonged or parturition is delayed. After birth, they develop a dermatologic condition known as ichthyosis which is associated with accumulation of cholesterol sulfate in the skin. Further metabolic studies should enhance our knowledge of the mechanisms which control the onset of labor, of the development of the epidermis, and of steroid metabolism in normal and abnormal individuals. We have also shown that steroid sulfatase synthesis is controlled by a gene located in a unique region (the dital tip of the short arm) of the human X chromosome. This gene escapes X chromosome inactivation, and this portion of the X chromosome is partially homologous to the Y chromosome and appears to engage in genetic recombination with it. We plan studies involving the cloning of the steroid sulfatase gene as well as other portions of the distal X short arm in order to gain insight into gene regulation in this portion of the genome, to investigate the possibility of X-Y recombination and to study alteration of sex chromosome segregation associated with X chromosome aneuploid states such as Turner's Syndrome and Kleinfelter's Syndrome.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD012178-10
Application #
3311812
Study Section
Mammalian Genetics Study Section (MGN)
Project Start
1978-08-01
Project End
1989-11-30
Budget Start
1987-12-01
Budget End
1988-11-30
Support Year
10
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Los Angeles County Harbor-UCLA Medical Center
Department
Type
DUNS #
City
Torrance
State
CA
Country
United States
Zip Code
90509
Li, X M; Salido, E C; Shapiro, L J (1999) The mouse alanine:glyoxylate aminotransferase gene (Agxt1): cloning, expression, and mapping to chromosome 1. Somat Cell Mol Genet 25:67-77
Li, X M; Alperin, E S; Salido, E et al. (1996) Characterization of the promoter region of human steroid sulfatase: a gene which escapes X inactivation. Somat Cell Mol Genet 22:105-17
Salido, E C; Li, X M; Yen, P H et al. (1996) Cloning and expression of the mouse pseudoautosomal steroid sulphatase gene (Sts). Nat Genet 13:83-6
Glass, I A; Passage, M; Bernatowicz, L et al. (1996) Generation of sequence-tagged sites from Xp22.3 by isolating common Alu-PCR products of radiation hybrids retaining overlapping human X chromosome fragments. Hum Genet 97:604-10
Li, X M; Salido, E C; Gong, Y et al. (1996) Cloning of the rat steroid sulfatase gene (Sts), a non-pseudoautosomal X-linked gene that undergoes X inactivation. Mamm Genome 7:420-4
Yen, P H; Salido, E; Shapiro, L et al. (1994) An EcoRI RFLP at the D6S509E locus. Hum Mol Genet 3:388
Wu, J; Ellison, J; Salido, E et al. (1994) Isolation and characterization of XE169, a novel human gene that escapes X-inactivation. Hum Mol Genet 3:153-60
Salido, E C; Passage, M B; Yen, P H et al. (1993) An evaluation of the inactive mouse X chromosome in somatic cell hybrids. Somat Cell Mol Genet 19:65-71
Li, X M; Shapiro, L J (1993) Three-step PCR mutagenesis for 'linker scanning'. Nucleic Acids Res 21:3745-8
Carrozzo, R; Ellison, J; Yen, P et al. (1992) Isolation and characterization of a yeast artificial chromosome (YAC) contig around the human steroid sulfatase gene. Genomics 12:7-12

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