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Novel androgen receptor-protein interactions as possible contributors to the pathogenesis of spinal and bulbar muscular atrophy

The human androgen receptor (hAR) is a ligand-activated, DNA-binding nuclear transcription factor. Mutations in the hAR result in varying degrees of androgen insensitivity (AI); they may play a predisposing or pathogenetic role in both prostate and breast cancer. Expansion of the hAR's N-terminal polymorphic Glutamine (Gln) repeat causes a late-onset progressive motoneuronopathy which is associated with mild androgen insensitivity: spinal and bulbar muscular atrophy (SBMA). SBMA belongs to a group of translated CAG trinucleotide repeat expansion neuronopathies that includes Huntington disease, dentatorubral-pallidoluysian atrophy and five distinct spinocerebellar ataxias. The fact that this group of disorders is caused by polyGln expansions in totally unrelated proteins, is one of the main reasons for postulating that a common gain-of-function mechanism must underlie their communal pathogenesis. This common pathogenetic mechanism is postulated to occur via aberrant protein interactions. / I undertook a search for hAR-interacting proteins using a yeast two-hybrid system. A human testes cDNA library was screened several times with two forms of an N-terminal fragment of the hAR: a normal (20 Gin) hAR and an expanded (50 Gin) hAR. A few candidate hAR-interacting proteins were isolated during the library screenings and I tested them for physiological relevance. / A second aspect of my project included the analysis of an aberrant 75-kD protein fragment generated in COS-1 cells transfected with a polyCAG-expanded (n = 44) hAR cDNA. Recent work in Huntington disease and spinocerebellar ataxia type 3 shows the accumulation of insoluble protein aggregates primarily in the nucleus of certain brain cells (Davies et al., 1997; Scherzinger et al., 1997; Paulson et al., 1997). I confirmed the presence of the aberrant hAR-fragment in the nucleus through western analysis of protein samples extracted from the nucleus.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20252
Date January 1997
CreatorsDe Tourreil, Sunita.
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Science (Department of Biology.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 001608891, proquestno: MQ44154, Theses scanned by UMI/ProQuest.

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