Salido E C, Li X M, Yen P H, Martin N, Mohandas T K, Shapiro L J
Department of Pediatrics, UCSF School of Medicine, San Francisco, California 94143, USA.
Nat Genet. 1996 May;13(1):83-6. doi: 10.1038/ng0596-83.
Steroid sulphatase (STS) is an important enzyme in steroid metabolism. The human STS gene has been cloned and mapped to Xp22.3, proximal to the pseudoautosomal region (PAR). Using quantitative differences in STS activity among various mouse strains, a segregation pattern consistent with autosomal linkage was first reported, but more recent studies have linked Sts to the mouse PAR. Failed attempts to clone the mouse Sts gene using human reagants (STS cDNA and anti-STS antibodies) suggest a substantial divergence between these genes. However, partial amino-terminal sequence from purified rat liver Sts is very similar to its human counterpart, and several domains are conserved among all the sulphatases. We followed a degenerate-primer reverse transcriptase-PCR (RT-PCR) approach to amplify a conserved fragment of the rat Sts cDNA that was then used to clone the mouse Sts cDNA. This 2.3-kb cDNA revealed 75% similarity with rat Sts cDNA, while it was only 63% similar to human STS cDNA. Transfection of STS(-) A9 cells with the mouse Sts cDNA restored STS enzymatic activity. Sts was also mapped physically to the distal end of the mouse sex chromosomes, and our backcross studies placed Sts distal to the 'obligatory' cross-over in male meiosis.
类固醇硫酸酯酶（STS）是类固醇代谢中的一种重要酶。人类STS基因已被克隆并定位到Xp22.3，靠近假常染色体区域（PAR）。利用不同小鼠品系间STS活性的定量差异，首次报道了一种与常染色体连锁一致的分离模式，但最近的研究已将Sts与小鼠PAR联系起来。使用人类试剂（STS cDNA和抗STS抗体）克隆小鼠Sts基因的尝试失败，表明这些基因之间存在很大差异。然而，纯化的大鼠肝脏Sts的部分氨基末端序列与其人类对应物非常相似，并且在所有硫酸酯酶中几个结构域是保守的。我们采用简并引物逆转录聚合酶链反应（RT-PCR）方法扩增大鼠Sts cDNA的一个保守片段，然后用于克隆小鼠Sts cDNA。这个2.3 kb的cDNA与大鼠Sts cDNA有75%的相似性，而与人类STS cDNA只有63%的相似性。用小鼠Sts cDNA转染STS(-) A9细胞可恢复STS酶活性。Sts也在物理上定位到小鼠性染色体的远端，我们的回交研究将Sts定位在雄性减数分裂中“必需”交叉的远端。
