Mutations in the amino-terminal domain of the human androgen receptor may be associated with partial androgen insensitivity and impaired transactivation in vitro

Exp Clin Endocrinol Diabetes. 2005 Sep;113(8):457-63. doi: 10.1055/s-2005-865770.

Abstract

The majority of genetic variations in the androgen receptor (AR) gene are point mutations leading to impairment of the DNA- or hormone-binding domains. The N-terminus encoded by the first exon of the AR-gene usually harbors disruptive mutations associated with complete androgen insensitivity syndrome (CAIS) while missense mutations related with partial androgen insensitivity syndrome (PAIS) are seemingly rare. We present a 46,XY male with scrotal hypospadias in whom we detected a S432 F point mutation within the N-terminus. Transient transfections of an AR expression plasmid carrying the S432 F mutation using Chinese Hamster Ovary (CHO) cells revealed a significant partial reduction in transactivation of the co-transfected androgen responsive (ARE) (2)TATA luciferase reporter gene thus confirming PAIS. In two further 46, XY patients with slight to moderate virilization defects, we detected an S411 N mutation, and a 9 base pair deletion leading to the loss of amino acids 409 to 411 (L-A-S), respectively. These mutations did not compromise AR-function under the chosen experimental settings. The S432 F-patient supports particular significance of the AR-N-terminus for mild forms of AIS while the functional role of the two further mutations remains unclear. The N-terminus is a species-specific AR-domain possibly also involved in contributing to target tissue selectivity of AR-actions via mediating co-regulator interactions. Therefore, mild molecular defects of the AR-N-terminus may not necessarily inhibit general transactivation properties using currently established reporter gene models.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Androgen-Insensitivity Syndrome / genetics
  • Androgen-Insensitivity Syndrome / metabolism*
  • Animals
  • CHO Cells
  • Child
  • Cricetinae
  • Cricetulus
  • Gene Expression / genetics
  • Gonadal Dysgenesis, 46,XY / genetics
  • Gonadal Dysgenesis, 46,XY / metabolism*
  • Humans
  • Infant, Newborn
  • Male
  • Mutation*
  • Protein Structure, Tertiary / genetics
  • Receptors, Androgen / genetics
  • Receptors, Androgen / metabolism*
  • Response Elements / genetics
  • Transcriptional Activation / genetics*

Substances

  • Receptors, Androgen