Differential splicing of human androgen receptor pre-mRNA in X-linked Reifenstein syndrome, because of a deletion involving a putative branch site.
The analysis of the androgen receptor (AR) gene, mRNA, and protein in a subject with X-linked Reifenstein syndrome (partial androgen insensitivity) is reported. The presence of two mature AR transcripts in genital skin fibroblasts of the patient is established, and, by reverse transcriptase-PCR and RNase transcription analysis, the wild-type transcript and a transcript in which exon 3 sequences are absent without disruption of the translational reading frame are identified. Sequencing and hybridization analysis show a deletion of > 6 kb in intron 2 of the human AR gene, starting 18 bp upstream of exon 3. The deletion includes the putative branch-point sequence (BPS) but not the acceptor splice site on the intron 2/exon 3 boundary. The deletion of the putative intron 2 BPS results in 90% inhibition of wild-type splicing. The mutant transcript encodes an AR protein lacking the second zinc finger of the DNA-binding domain. Western/immunoblotting analysis is used to show that the mutant AR protein is expressed in genital skin fibroblasts of the patient. The residual 10% wild-type transcript can be the result of the use of a cryptic BPS located 63 bp upstream of the intron 2/exon 3 boundary of the mutant AR gene. The mutated AR protein has no transcription-activating potential and does not influence the transactivating properties of the wild-type AR, as tested in cotransfection studies. It is concluded that the partial androgen-insensitivity syndrome of this patient is the consequence of the limited amount of wild-type AR protein expressed in androgen target cells, resulting from the deletion of the intron 2 putative BPS.
Ris-Stalpers
C
C
Department of Endocrinology and Reproduction, Erasmus University, Rotterdam, The Netherlands.
Verleun-Mooijman
M C
MC
de Blaeij
T J
TJ
Degenhart
H J
HJ
Trapman
J
J
Brinkmann
A O
AO
D017398:Alternative Splicing; D001483:Base Sequence; D016384:Consensus Sequence; D012734:Disorders of Sex Development / Q000235:genetics*; D005347:Fibroblasts / Q000378:metabolism; D005796:Genes; D008040:Genetic Linkage; D006801:Humans; D007438:Introns / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012322:RNA Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D011944:Receptors, Androgen / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D017384:Sequence Deletion; D013577:Syndrome; D014158:Transcription, Genetic; D014960:X Chromosome; D016335:Zinc Fingers / Q000235:genetics
D012322:RNA Precursors; D012333:RNA, Messenger; D011944:Receptors, Androgen