Androgens regulate the binding of endogenous HuR to the AU-rich 3'UTRs of HIF-1alpha and EGF mRNA.
The 3'UTRs of mammalian HIF-1alpha and EGF mRNA contain several highly conserved AU-rich elements (ARE) known to control the turnover of labile mRNAs by binding ARE-binding proteins that regulate nucleocytoplasmic shuttling, translation, and degradation. Androgens regulate the level and subcellular shuttling of HuR, a major ARE-binding protein that stabilizes many ARE-mRNAs. Pull down of biotinylated 3'UTRs of HIF-1alpha or EGF enriches HuR on blots from Jurkat cell lysates 5-fold, and enriches the amount of RNase-protected biotinylated RNA that comigrates with HuR approximately 10-fold. Dihydrotestosterone treatment decreases the HuR-protected riboprobe pulled down from total Jurkat cell lysates by 30-40%, apparently reflecting shifts in HuR from the nucleus to the cytoplasm. Androgen treatment also changes the amount of HuR-protected riboprobe pulled down from a PC-3 clone expressing a functional androgen receptor. The shift in the amount of riboprobe bound by HuR suggests that androgen is up-regulating endogenous ARE-mRNAs that can compete for binding endogenous HuR. These changes in the shuttling and ARE-binding of endogenous HuR indicate that androgen can act posttranscriptionally to regulate ARE-mRNAs, including HIF-1alpha and EGF.
Medical Research Service, VA WNYHS, 3495 Bailey Avenue, Buffalo, NY 14215, USA. sheflin@acsu.buffalo.edu
Lowell G
LG
Sheflin
Ai-Ping
AP
Zou
Stephen W
SW
Spaulding
D020413:3' Untranslated Regions; D000728:Androgens / Q000378:metabolism; D000954:Antigens, Surface / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; D004815:Epidermal Growth Factor / Q000235:genetics*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D017874:Immediate-Early Proteins / Q000378:metabolism; D019169:Jurkat Cells; D015335:Molecular Probes; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*; D051816:Tristetraprolin
D020413:3' Untranslated Regions; D000728:Androgens; D000954:Antigens, Surface; D004268:DNA-Binding Proteins; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; C098770:ELAVL1 protein, human; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D017874:Immediate-Early Proteins; D015335:Molecular Probes; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D051816:Tristetraprolin; C497552:ZFP36 protein, human; D004815:Epidermal Growth Factor