Mutations in the Amino-Terminal Domain of the Human Androgen Receptor may be Associated with Partial Androgen Insensitivity and Impaired Transactivation in vitro

2005 ◽  
Vol 113 (08) ◽  
pp. 457-463 ◽  
Author(s):  
P.-M. Holterhus ◽  
R. Werner ◽  
D. Struve ◽  
B. Hauffa ◽  
C. Schroeder ◽  
...  
2008 ◽  
Vol 41 (5) ◽  
pp. 301-314 ◽  
Author(s):  
Philippa Davies ◽  
Kate Watt ◽  
Sharon M Kelly ◽  
Caroline Clark ◽  
Nicholas C Price ◽  
...  

Poly-amino acid repeats, especially long stretches of glutamine (Q), are common features of transcription factors and cell-signalling proteins and are prone to expansion, resulting in neurodegenerative diseases. The amino-terminal domain of the androgen receptor (AR-NTD) has a poly-Q repeat between 9 and 36 residues, which when it expands above 40 residues results in spinal bulbar muscular atrophy. We have used spectroscopy and biochemical analysis to investigate the structural consequences of an expanded repeat (Q45) or removal of the repeat (ΔQ) on the folding of the AR-NTD. Circular dichroism spectroscopy revealed that in aqueous solution, the AR-NTD has a relatively limited amount of stable secondary structure. Expansion of the poly-Q repeat resulted in a modest increase in α-helix structure, while deletion of the repeat resulted in a small loss of α-helix structure. These effects were more pronounced in the presence of the structure-promoting solvent trifluoroethanol or the natural osmolyte trimethylamine N-oxide. Fluorescence spectroscopy showed that the microenvironments of four tryptophan residues were also altered after the deletion of the Q stretch. Other structural changes were observed for the AR-NTDQ45 polypeptide after limited proteolysis; in addition, this polypeptide not only showed enhanced binding of the hydrophobic probe 8-anilinonaphthalene-1-sulphonic acid but was more sensitive to urea-induced unfolding. Taken together, these findings support the view that the presence and length of the poly-Q repeat modulate the folding and structure of the AR-NTD.


2001 ◽  
Vol 75 (7) ◽  
pp. 3230-3239 ◽  
Author(s):  
Miran Yoon ◽  
Deborah H. Smith ◽  
Peter Ward ◽  
Francisco J. Medrano ◽  
Aneel K. Aggarwal ◽  
...  

ABSTRACT The unique ability of adeno-associated virus type 2 (AAV) to site-specifically integrate its genome into a defined sequence on human chromosome 19 (AAVS1) makes it of particular interest for use in targeted gene delivery. The objective underlying this study is to provide evidence for the feasibility of retargeting site-specific integration into selected loci within the human genome. Current models postulate that AAV DNA integration is initiated through the interactions of the products of a single viral open reading frame,REP, with sequences present in AAVS1 that resemble the minimal origin for AAV DNA replication. Here, we present a cell-free system designed to dissect the Rep functions required to target site-specific integration using functional chimeric Rep proteins derived from AAV Rep78 and Rep1 of the closely related goose parvovirus. We show that amino-terminal domain exchange efficiently redirects the specificity of Rep to the minimal origin of DNA replication. Furthermore, we establish that the amino-terminal 208 amino acids of Rep78/68 constitute a catalytic domain of Rep sufficient to mediate site-specific endonuclease activity.


FEBS Letters ◽  
2007 ◽  
Vol 581 (17) ◽  
pp. 3197-3203 ◽  
Author(s):  
Stephanie Herring ◽  
Alexandre Ambrogelly ◽  
Sarath Gundllapalli ◽  
Patrick O'Donoghue ◽  
Carla R. Polycarpo ◽  
...  

2016 ◽  
Vol 291 (42) ◽  
pp. 22231-22243 ◽  
Author(s):  
Carmen A. Banuelos ◽  
Iran Tavakoli ◽  
Amy H. Tien ◽  
Daniel P. Caley ◽  
Nasrin R. Mawji ◽  
...  

2000 ◽  
Vol 113 (7) ◽  
pp. 1267-1276 ◽  
Author(s):  
F. Granes ◽  
J.M. Urena ◽  
N. Rocamora ◽  
S. Vilaro

The syndecan family of heparan sulfate proteoglycans is known to associate with the actin cytoskeleton, possibly transducing signals from the extracellular matrix. In the search for proteins that could mediate the association of syndecan-2 with the actin cytoskeleton we found that ezrin, a protein which links membrane receptors to the cytoskeleton, coimmunoprecipitated with syndecan-2 in COS-1 cells. In vitro assays indicated a direct association between the amino-terminal domain of ezrin and the cytoplasmic domain of syndecan-2. Confocal microscopy showed colocalization of ezrin and syndecan-2 in actin-rich microspikes in COS-1 cells. The syndecan-2/ezrin protein complex was resistant to 0.2% Triton X-100 extraction but the syndecan-2/amino-terminal domain of ezrin complex was not, which indicated that carboxi-terminal domain of ezrin is involved in the cytoskeleton anchorage of this protein complex. Additionally we observed that the activation of rhoA GTPase increased syndecan-2 insolubility in 0.2% Triton X-100 and syndecan-2/ezrin association. Taken together, these results indicate that ezrin connects syndecan-2 to the actin cytoskeleton.


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