Activation of the DNA-dependent protein kinase stimulates nuclear export of the androgen receptor in vitro
Graduate School of Biomedical Sciences; Department of Cell Biology
Life Sciences | Medicine and Health Sciences
The androgen receptor undergoes nuclear import in response to ligand, but the mechanism by which it undergoes nuclear export is poorly understood. We developed a permeabilized cell assay to characterize nuclear export of the androgen receptor in LNCaP prostate cancer cells. We found that nuclear export of endogenous androgen receptor can be stimulated by short double-stranded DNA oligonucleotides. This androgen receptor export pathway is dependent on ATP hydrolysis and is enhanced by phosphatase inhibition with okadaic acid. Fluorescence recovery after photobleaching in permeabilized cells, under the conditions that stimulate androgen receptor export, suggested that double-stranded DNA-dependent export does not simply reflect the relief of a nuclear retention mechanism. A radiolabeled androgen was used to show that the androgen receptor remains ligand-bound during translocation through the nuclear pore complex. A specific inhibitor to the DNA-dependent protein kinase, NU7026, inhibits androgen receptor export and phosphorylation. In living cells, NU7026 treatment increases androgen-dependent transcription from endogenous genes that are regulated by androgen receptor. We suggest that DNA-dependent protein kinase phosphorylation of the androgen receptor, or an interacting component, helps target the androgen receptor for export from the nucleus.
DOI of Published Version
J Biol Chem. 2008 Apr 18;283(16):10568-80. Epub 2008 Feb 12. Link to article on publisher's site
The Journal of biological chemistry
Shank, Leonard C.; Kelley, Joshua B.; Gioeli, Daniel G.; Yang, Chun-Song; Spencer, Adam; Allison, Lizabeth A.; and Paschal, Bryce Mark, "Activation of the DNA-dependent protein kinase stimulates nuclear export of the androgen receptor in vitro" (2008). GSBS Student Publications. 1449.