Characterization of the androgen receptor (AR) in sexual differntiation to androgen insensitivity syndrome (AIS).

AIS的分子基础最终是通过在不同形式的该综合征个体中识别编码AR的基因突变而建立的。我们报告了睾丸女性化综合征和Reifenstein综合征的AR基因点突变。在利用源自生殖器的成纤维细胞进行的放射受体实验中，AR激素结合域的这些点突变导致了它们的耐热性，在将靶基因转染到COS7细胞后，通过反激活荧光素酶实验证实了这一点。与野生型相比，1个突变体表达质粒显著降低了酶转活性（58.5%，P< 0）。M807V和R840H两个突变体表达质粒与野生型相比显著降低了报告基因活性（64.5%，P< 0.05）。两种突变中任何一种的转激活试验均未显示报告基因活性与野生型有任何差异。虽然将两种疏水氨基酸中的一种替换为亲水氨基酸，但与野生型相比，突变表达质粒显著降低了报告基因的活性（34.8%，P< 0.05）。我们认为，产生疏水氨基酸取代亲水氨基酸的点突变可能是ALS患者生殖器模糊表型的主要原因之一。我们正在进行AR的差异显示试验，以研究目标基因的第二信息。

The molecular basis of AIS was ultimately established by identification of mutations in the gene encoding the AR in individuals with various forms of this syndrome. We report point mutations in the AR gene of testicular feminization syndrome, and Reifenstein syndrome. These point mutations in the hormone binding domain of the AR were responsible for their thermolability in the radioreceptor assay using fibloblast cells derived from genitalia, which were confirmed through transactivation luciferase assay after transfection of the target genes into COS7 cells. The one mutant expression plasmid significantly decreased the transactivation activity in comparison with that of a wild type (58.5%, P<O.05), and two mutants expression plasmid (M807V, and R840H) significantly decreased the reporter gene activity in comparison with that of a wild type (64.5%, P<O.05). Transactivation assay with one of two mutations didn't show any difference of the reporter gene activity from that of a wild type. Although the replacement of one of two hydrophobic aminoacids for hydrophillic amino acid transfected into the one mutant expression plasmid significantly decreased the reporter gene activity in comparison with that of a wild type (34.8%, P<O.05). We suggest that the point mutation generating the replacement of hydrophobic amino acid for hydrophilic one could be one of the major causes for an ambiguous phenotype of genitalia in patients with ALS.We are undergoing differential display assay of the AR to investigate second message of the target gene.