TY - JOUR
T1 - CRM 1-mediated degradation and agonist-induced down-regulation of β-adrenergic receptor mRNAs
AU - Bai, Ying
AU - Lu, Huafei
AU - Machida, Curtis A.
N1 - Funding Information:
This research was supported by NIH MH 63137, and by the National American Heart Association (AHA) grant 0250017N. CAM was also a former recipient of an AHA Established Investigator Award and was a recipient of the 2003 Dean's Research Grant Award from the OHSU School of Dentistry.
PY - 2006/10
Y1 - 2006/10
N2 - The β1-adrenergic receptor (β1-AR) mRNAs are post-transcriptionally regulated at the level of mRNA stability and undergo accelerated agonist-mediated degradation via interaction of its 3′ untranslated region (UTR) with RNA binding proteins, including the HuR nuclear protein. In a previous report [Kirigiti et al. (2001). Mol. Pharmacol. 60:1308-1324], we examined the agonist-mediated down-regulation of the rat β1-AR mRNAs, endogenously expressed in the rat C6 cell line and ectopically expressed in transfectant hamster DDT1MF2 and rat L6 cells. In this report, we determined that isoproterenol treatment of neonatal rat cortical neurons, an important cell type expressing β1-ARs in the brain, results in significant decreases in β1-AR mRNA stability, while treatment with leptomycin B, an inhibitor of the nuclear export receptor CRM 1, results in significant increases in β1-AR mRNA stability and nuclear retention. UV-crosslinking/immunoprecipitation and glycerol gradient fractionation analyses indicate that the β1-AR 3′ UTR recognize complexes composed of HuR and multiple proteins, including CRM 1. Cell-permeable peptides containing the leucine-rich nuclear export signal (NES) were used as inhibitors of CRM 1-mediated nuclear export. When DDT1MF2 transfectants were treated with isoproterenol and peptide inhibitors, only the co-addition of the NES inhibitor reversed the isoproterenol-induced reduction of β1-AR mRNA levels. Our results suggest that CRM 1-dependent NES-mediated mechanisms influence the degradation and agonist-mediated down-regulation of the β1-AR mRNAs.
AB - The β1-adrenergic receptor (β1-AR) mRNAs are post-transcriptionally regulated at the level of mRNA stability and undergo accelerated agonist-mediated degradation via interaction of its 3′ untranslated region (UTR) with RNA binding proteins, including the HuR nuclear protein. In a previous report [Kirigiti et al. (2001). Mol. Pharmacol. 60:1308-1324], we examined the agonist-mediated down-regulation of the rat β1-AR mRNAs, endogenously expressed in the rat C6 cell line and ectopically expressed in transfectant hamster DDT1MF2 and rat L6 cells. In this report, we determined that isoproterenol treatment of neonatal rat cortical neurons, an important cell type expressing β1-ARs in the brain, results in significant decreases in β1-AR mRNA stability, while treatment with leptomycin B, an inhibitor of the nuclear export receptor CRM 1, results in significant increases in β1-AR mRNA stability and nuclear retention. UV-crosslinking/immunoprecipitation and glycerol gradient fractionation analyses indicate that the β1-AR 3′ UTR recognize complexes composed of HuR and multiple proteins, including CRM 1. Cell-permeable peptides containing the leucine-rich nuclear export signal (NES) were used as inhibitors of CRM 1-mediated nuclear export. When DDT1MF2 transfectants were treated with isoproterenol and peptide inhibitors, only the co-addition of the NES inhibitor reversed the isoproterenol-induced reduction of β1-AR mRNA levels. Our results suggest that CRM 1-dependent NES-mediated mechanisms influence the degradation and agonist-mediated down-regulation of the β1-AR mRNAs.
KW - Agonist-induced down-regulation
KW - CRM 1
KW - mRNA degradation and stability
KW - β-adrenergic receptor
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U2 - 10.1016/j.bbamcr.2006.08.009
DO - 10.1016/j.bbamcr.2006.08.009
M3 - Article
C2 - 16997396
AN - SCOPUS:33749046895
SN - 0167-4889
VL - 1763
SP - 1076
EP - 1089
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
IS - 10
ER -