Published-Ahead-of-Print May 23, 2007, DOI:10.2164/jandrol.107.002691
Journal of Andrology, Vol. 28, No. 5, September/October 2007
Copyright © American Society of Andrology
DOI: 10.2164/jandrol.107.002691
L859F Mutation in Androgen Receptor Gene Results in Complete Loss of Androgen Binding to the Receptor
SINGH RAJENDER,
LALJI SINGH AND
KUMARASAMY THANGARAJ
From the Centre for Cellular and Molecular Biology, Hyderabad,
India.
|
Correspondence to: Dr K. Thangaraj, Centre for Cellular and Molecular Biology,
Uppal Rd, Hyderabad 500 007, India (e-mail:
thangs{at}ccmb.res.in). |
Androgens drive male secondary sexual differentiation and maturation.
Mutations in the androgen receptor (AR) gene cause an array of
abnormal sex differentiation phenotypes in humans, ranging from mild through
partial to complete androgen insensitivity. Earlier, we reported a C3693T
missense mutation in the AR gene in a familial case of complete
androgen insensitivity syndrome (CAIS), resulting in the replacement of a
highly conserved leucine residue with phenylalanine (L859F) in ligand-binding
domain (LBD) of the receptor. In silico analysis and the information from the
crystal structure of AR-LBD indicated that the residue L859, located in helix
10 of AR protein, plays a significant role in overall architecture of the
ligand-binding pocket. From this information we anticipated that the mutation
might have resulted in the loss of the ligand binding to the receptor. In the
present study, we have conducted the in vitro functional assays for this
mutation. The mutation resulted in highly significant loss of the ligand
binding to the receptor. The loss of ligand binding and subsequent AR function
was confirmed by the transactivation assay, in which we observed very little
activation of the reporter gene expressed under the control of the ligand-AR
complex.
Key words: XY sex primary amenorrhea reversal, primary amenorrhea, androgens, complete androgen insensitivity syndrome, Leydig cell hyperplasia, ligand binding
Copyright © 2007 by The American Society of Andrology.