Ar-arg840cys Mutation Analysis Of The Functional Mechanism Of Androgen Insensitivity Syndrome (ais) Patients

Androgen Insensitivity Syndrome (AIS) is an X-linked disorder of male sexual differentiation, caused by an absent or dysfunctional androgen receptor (AR). Mutations in the AR gene result in a wide range of AIS phenotypes. The phenotypic spectrum ranges from a complete female phenotype to diverse male phenotype deficiency.We have recently reported an AR-Arg840Cys from a large Chinese family affected with AIS. Genetic analysis showed that the disease trait was completely linked to an Arg840Cys mutant of AR and that all patients shared an identical Arg840Cys mutant but displayed large variation in disease phenotypes. Some of the affected males were infertile and had gynecomastia and/or hypospadias but some had fathered children normally. With an attempt to unveil the molecular mechanisms of the pleiotropic phenomenon, we have created genital skin fibroblast (GSF) cell lines directly from three patients in a Chinese family affected with androgen insensitivity syndrome (AIS). The donors of the GSF samples represent a typical pattern of the disease phenotypic variation in the affected members in the family. By making use of these primary cell lines, we find that this mutant AR has not influenced a normal androgen-binding capacity at 37℃ but has a reduced affinity for androgens and is thermolabile in the two cell lines whose donors suffer more severe disease symptom. The confocal analysis reveals that the impaired unclear trafficking of the androgen-receptor in the cell lines is highly correlated with severity of the donors' disease phenotype. Comparison in transcriptional activation between the normal and the mutant AR shows that the transactivity is significantly weakened in the mutant cell lines and the extent of the reduced transactivity depends on the donors' disease symptom. Moreover, the impaired transactivity is recovered, when induced by the plasmids carrying normal androgen receptors, to a normal level in one of the three cell lines whose donor has the mildest AIS. It suggested that there would be an effective mechanism that acts a role in regulating and compensating the defective transmission of the activation signalOur data reveals that although etiology of AIS is monogenic, the disease phenotype varies because the main biological functions of the AR such as bindingaffinity, trafficking and transcriptional activation are altered to different degrees. The study also reveals existence of the other factors that act very likely interactive roles with the AR gene in contributing to the disease phenotypic variation. As an initial attempt to explore the interaction between the AR and its co-regulators, we carried out the 2D-PAGE and suppression subtractive hybridization (SSH) experiments to hunt for these co-regulators.