The androgen receptor acetylation site regulates cAMP and AKT but not ERK-induced activity.
The androgen receptor (AR) regulates ligand-dependent gene transcription upon binding specific DNA sequences. The AR conveys both trans-activation and trans-repression functions, which together contribute to prostate cellular growth, differentiation, and apoptosis. Like histone H3, the AR is post-translationally modified by both acetylation and phosphorylation. The histone acetyltransferase p300 transactivates the AR and directly acetylates the AR in vitro at a conserved motif. Point mutations of the AR acetylation motif that abrogate acetylation reduce trans-activation by p300 without affecting the trans-repression function of the AR. The current studies assessed the functional relationship between acetylation and phosphorylation of the AR. Herein trans-activation of the AR acetylation site mutants were enhanced by the p42/p44 MAPK pathway but were defective in regulation by protein kinase A (PKA) signaling. PKA inhibition augmented ARwt activity but not AR acetylation mutant gene reporter activity and association at an androgen response element in chromatin immunoprecipitation assays. Mutations of the lysine residues at the AR acetylation site reduced trichostatin A (TSA) responsiveness and ligand-induced phosphorylation of the AR. The AR acetylation site mutant formed ligand-induced phosphorylation-dependent isoforms with distinguishable characteristics from wild type AR as determined with two-dimensional electrophoresis. Conversely, point mutation of a subset of AR phosphorylation sites reduced trichostatin A responsiveness and trans-activation by histone acetyltransferases. Together these studies suggest that acetylation and phosphorylation of the AR are linked events and that the conserved AR lysine motif contributes to a select subset of pathways governing AR activity.
Fu
Maofu
M
Department of Oncology, Georgetown University Medical Center, Washington, D C 20057, USA.
Rao
Mahadev
M
Wu
Kongming
K
Wang
Chenguang
C
Zhang
Xueping
X
Hessien
Mohamed
M
Yeung
Yee-Guide
YG
Gioeli
Daniel
D
Weber
Michael J
MJ
Pestell
Richard G
RG
D000107:Acetylation; D000818:Animals; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D008024:Ligands; D008239:Lysine / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000502:physiology; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D017354:Point Mutation; D011471:Prostatic Neoplasms / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D008024:Ligands; D010710:Phosphates; D011518:Proto-Oncogene Proteins; D011944:Receptors, Androgen; C012589:trichostatin A; D000242:Cyclic AMP; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D006655:Histone Deacetylases; D008239:Lysine