SUMO-specific protease 1 (SENP1) reverses the hormone-augmented SUMOylation of androgen receptor and modulates gene responses in prostate cancer cells.
The acceptor sites for small ubiquitin-like modifier (SUMO) are conserved in the N-terminal domains of several nuclear receptors. Here, we show that androgens induce rapid and dynamic conjugation of SUMO-1 to androgen receptor (AR). Nuclear import of AR is not sufficient for SUMOylation, because constitutively nuclear apo-ARs or antagonist-bound ARs are only very weakly modified by SUMO-1 in comparison with agonist-bound ARs. Of the SUMO-specific proteases (SENP)-1, -2, -3, -5, and -6, only SENP1 and SENP2 are efficient in cleaving AR-SUMO-1 conjugates in intact cells and in vitro. Both SENP1 and -2 are nuclear and found at sites proximal to AR. Their expression promotes AR-dependent transcription, but in a promoter-selective fashion. SENP1 and -2 stimulated the activity of holo-AR on compound androgen response element-containing promoters. The effects of SENP1 and -2 on AR-dependent transcription were dependent on catalytic activity and required intact SUMO acceptor sites in AR, indicating that their coactivating effects are mainly due to their direct isopeptidase activity on holo-AR. In prostate cancer cells, ectopic expression of SENP1, but not that of SENP2, increased the transcription activity of endogenous AR. Silencing of SENP1 attenuated the expression of several AR target genes and blunted androgen-stimulated growth of LNCaP cells. Our results indicate that SENP1 reverses the ligand-induced SUMOylation of AR and helps fine tune the cellular responses to androgens in a target promoter-selective manner.
Kaikkonen
Sanna
S
Institute of Biomedicine/Medical Biochemistry, University of Kuopio, FI-70211 Kuopio, Finland.
Jääskeläinen
Tiina
T
Karvonen
Ulla
U
Rytinki
Miia M
MM
Makkonen
Harri
H
Gioeli
Daniel
D
Paschal
Bryce M
BM
Palvimo
Jorma J
JJ
D000107:Acetylation / Q000187:drug effects; D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism; D002522:Chlorocebus aethiops; D003546:Cysteine Endopeptidases; D010450:Endopeptidases / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008239:Lysine / Q000378:metabolism; D008297:Male; D010766:Phosphorylation / Q000187:drug effects; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism*; D011487:Protein Conformation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D021381:Protein Transport; D011944:Receptors, Androgen / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D025842:SUMO-1 Protein / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D000728:Androgens; D011944:Receptors, Androgen; D025842:SUMO-1 Protein; D010450:Endopeptidases; C404512:SENP1 protein, human; D003546:Cysteine Endopeptidases; D008239:Lysine