Abstract
RVR/Rev-erb beta/BD73 is an orphan steroid receptor that has no known ligand in the "classical' sense. RVR binds as a monomer to an element which consists of an A/T-rich sequence upstream of the consensus hexameric half-site. However, RVR does not activate transcription and blocks transactivation of this element by ROR/RZR. The mechanism of RVR action remains obscure, hence we used the GAL4 hybrid system to identify and characterize an active transcriptional silencer in the ligand binding domain (LBD) of RVR. Rigorous deletion and mutational analysis demonstrated that this repressor domain is encoded by amino acids 416-449 of RVR. Furthermore, we demonstrated that efficient repression is dependent on the so-called LBD-specific signature motif, (F/W)AKxxxxFxxLxxxDQxxLL (which spans loop3-4 and helix 4) and helix 5 (H5; identified in the crystal structures of the steroid receptor LBDs). Although RVR is expressed in many adult tissues, including skeletal muscle, and during embryogenesis, its physiological function in differentiation and mammalian development remains unknown. Since other 'orphans', e.g. COUP-TF II and Rev-erbA alpha, have been demonstrated to regulate muscle and adipocyte differentiation, we investigated the expression and functional role of RVR during mouse myogenesis. In C2C12 myogenic cells, RVR mRNA was detected in proliferating myoblasts and was suppressed when the cells were induced to differentiate into post-mitotic, multinucleated myotubes by serum withdrawal. This decrease in RVR mRNA correlated with the appearance of muscle-specific markers (e.g. myogenin mRNA). RVR 'loss of function' studies by constitutive over-expression of a dominant negative RVR delta E resulted in increased levels of p21Cip1/Waf1 and myogenin mRNAs after serum withdrawal. Time course studies indicated that expression of RVR delta E mRNA results in the precocious induction and accumulation of myogenin and p21 mRNAs after serum withdrawal. In addition, we demonstrated that over-expression of the COUP-TF II and Rev-erbA alpha receptors in C2C12 cells completely blocked induction of p21 mRNA after serum withdrawal. In conclusion, our studies identified a potent transcriptional repression domain in RVR, characterized critical amino acids within the silencing region and provide evidence for the physiological role of RVR during myogenesis.
Full Text
The Full Text of this article is available as a PDF (190.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Adelmant G., Bègue A., Stéhelin D., Laudet V. A functional Rev-erb alpha responsive element located in the human Rev-erb alpha promoter mediates a repressing activity. Proc Natl Acad Sci U S A. 1996 Apr 16;93(8):3553–3558. doi: 10.1073/pnas.93.8.3553. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bains W., Ponte P., Blau H., Kedes L. Cardiac actin is the major actin gene product in skeletal muscle cell differentiation in vitro. Mol Cell Biol. 1984 Aug;4(8):1449–1453. doi: 10.1128/mcb.4.8.1449. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bonnelye E., Vanacker J. M., Desbiens X., Begue A., Stehelin D., Laudet V. Rev-erb beta, a new member of the nuclear receptor superfamily, is expressed in the nervous system during chicken development. Cell Growth Differ. 1994 Dec;5(12):1357–1365. [PubMed] [Google Scholar]
- Bourguet W., Ruff M., Chambon P., Gronemeyer H., Moras D. Crystal structure of the ligand-binding domain of the human nuclear receptor RXR-alpha. Nature. 1995 Jun 1;375(6530):377–382. doi: 10.1038/375377a0. [DOI] [PubMed] [Google Scholar]
- Casanova J., Helmer E., Selmi-Ruby S., Qi J. S., Au-Fliegner M., Desai-Yajnik V., Koudinova N., Yarm F., Raaka B. M., Samuels H. H. Functional evidence for ligand-dependent dissociation of thyroid hormone and retinoic acid receptors from an inhibitory cellular factor. Mol Cell Biol. 1994 Sep;14(9):5756–5765. doi: 10.1128/mcb.14.9.5756. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davis R. L., Weintraub H., Lassar A. B. Expression of a single transfected cDNA converts fibroblasts to myoblasts. Cell. 1987 Dec 24;51(6):987–1000. doi: 10.1016/0092-8674(87)90585-x. [DOI] [PubMed] [Google Scholar]
- Dowhan D. H., Downes M., Sturm R. A., Muscat G. E. Identification of deoxyribonucleic acid sequences that bind retinoid-X receptor-gamma with high affinity. Endocrinology. 1994 Dec;135(6):2595–2607. doi: 10.1210/endo.135.6.7988448. [DOI] [PubMed] [Google Scholar]
- Downes M., Carozzi A. J., Muscat G. E. Constitutive expression of the orphan receptor, Rev-erbA alpha, inhibits muscle differentiation and abrogates the expression of the myoD gene family. Mol Endocrinol. 1995 Dec;9(12):1666–1678. doi: 10.1210/mend.9.12.8614403. [DOI] [PubMed] [Google Scholar]
- Dumas B., Harding H. P., Choi H. S., Lehmann K. A., Chung M., Lazar M. A., Moore D. D. A new orphan member of the nuclear hormone receptor superfamily closely related to Rev-Erb. Mol Endocrinol. 1994 Aug;8(8):996–1005. doi: 10.1210/mend.8.8.7997240. [DOI] [PubMed] [Google Scholar]
- Evans R. M. The steroid and thyroid hormone receptor superfamily. Science. 1988 May 13;240(4854):889–895. doi: 10.1126/science.3283939. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Forman B. M., Chen J., Blumberg B., Kliewer S. A., Henshaw R., Ong E. S., Evans R. M. Cross-talk among ROR alpha 1 and the Rev-erb family of orphan nuclear receptors. Mol Endocrinol. 1994 Sep;8(9):1253–1261. doi: 10.1210/mend.8.9.7838158. [DOI] [PubMed] [Google Scholar]
- Giguère V., Tini M., Flock G., Ong E., Evans R. M., Otulakowski G. Isoform-specific amino-terminal domains dictate DNA-binding properties of ROR alpha, a novel family of orphan hormone nuclear receptors. Genes Dev. 1994 Mar 1;8(5):538–553. doi: 10.1101/gad.8.5.538. [DOI] [PubMed] [Google Scholar]
- Green S., Chambon P. Nuclear receptors enhance our understanding of transcription regulation. Trends Genet. 1988 Nov;4(11):309–314. doi: 10.1016/0168-9525(88)90108-4. [DOI] [PubMed] [Google Scholar]
- Gu W., Schneider J. W., Condorelli G., Kaushal S., Mahdavi V., Nadal-Ginard B. Interaction of myogenic factors and the retinoblastoma protein mediates muscle cell commitment and differentiation. Cell. 1993 Feb 12;72(3):309–324. doi: 10.1016/0092-8674(93)90110-c. [DOI] [PubMed] [Google Scholar]
- Guo K., Wang J., Andrés V., Smith R. C., Walsh K. MyoD-induced expression of p21 inhibits cyclin-dependent kinase activity upon myocyte terminal differentiation. Mol Cell Biol. 1995 Jul;15(7):3823–3829. doi: 10.1128/mcb.15.7.3823. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Halevy O., Novitch B. G., Spicer D. B., Skapek S. X., Rhee J., Hannon G. J., Beach D., Lassar A. B. Correlation of terminal cell cycle arrest of skeletal muscle with induction of p21 by MyoD. Science. 1995 Feb 17;267(5200):1018–1021. doi: 10.1126/science.7863327. [DOI] [PubMed] [Google Scholar]
- Harding H. P., Lazar M. A. The monomer-binding orphan receptor Rev-Erb represses transcription as a dimer on a novel direct repeat. Mol Cell Biol. 1995 Sep;15(9):4791–4802. doi: 10.1128/mcb.15.9.4791. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harding H. P., Lazar M. A. The orphan receptor Rev-ErbA alpha activates transcription via a novel response element. Mol Cell Biol. 1993 May;13(5):3113–3121. doi: 10.1128/mcb.13.5.3113. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hasty P., Bradley A., Morris J. H., Edmondson D. G., Venuti J. M., Olson E. N., Klein W. H. Muscle deficiency and neonatal death in mice with a targeted mutation in the myogenin gene. Nature. 1993 Aug 5;364(6437):501–506. doi: 10.1038/364501a0. [DOI] [PubMed] [Google Scholar]
- Matsushime H., Roussel M. F., Ashmun R. A., Sherr C. J. Colony-stimulating factor 1 regulates novel cyclins during the G1 phase of the cell cycle. Cell. 1991 May 17;65(4):701–713. doi: 10.1016/0092-8674(91)90101-4. [DOI] [PubMed] [Google Scholar]
- Muscat G. E., Downes M., Dowhan D. H. Regulation of vertebrate muscle differentiation by thyroid hormone: the role of the myoD gene family. Bioessays. 1995 Mar;17(3):211–218. doi: 10.1002/bies.950170307. [DOI] [PubMed] [Google Scholar]
- Muscat G. E., Gobius K., Emery J. Proliferin, a prolactin/growth hormone-like peptide represses myogenic-specific transcription by the suppression of an essential serum response factor-like DNA-binding activity. Mol Endocrinol. 1991 Jun;5(6):802–814. doi: 10.1210/mend-5-6-802. [DOI] [PubMed] [Google Scholar]
- Muscat G. E., Rea S., Downes M. Identification of a regulatory function for an orphan receptor in muscle: COUP-TF II affects the expression of the myoD gene family during myogenesis. Nucleic Acids Res. 1995 Apr 25;23(8):1311–1318. doi: 10.1093/nar/23.8.1311. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Olson E. N. Interplay between proliferation and differentiation within the myogenic lineage. Dev Biol. 1992 Dec;154(2):261–272. doi: 10.1016/0012-1606(92)90066-p. [DOI] [PubMed] [Google Scholar]
- Olson E. N. Signal transduction pathways that regulate skeletal muscle gene expression. Mol Endocrinol. 1993 Nov;7(11):1369–1378. doi: 10.1210/mend.7.11.8114752. [DOI] [PubMed] [Google Scholar]
- Parker S. B., Eichele G., Zhang P., Rawls A., Sands A. T., Bradley A., Olson E. N., Harper J. W., Elledge S. J. p53-independent expression of p21Cip1 in muscle and other terminally differentiating cells. Science. 1995 Feb 17;267(5200):1024–1027. doi: 10.1126/science.7863329. [DOI] [PubMed] [Google Scholar]
- Power R. F., Lydon J. P., Conneely O. M., O'Malley B. W. Dopamine activation of an orphan of the steroid receptor superfamily. Science. 1991 Jun 14;252(5012):1546–1548. doi: 10.1126/science.2047861. [DOI] [PubMed] [Google Scholar]
- Rangarajan P. N., Umesono K., Evans R. M. Modulation of glucocorticoid receptor function by protein kinase A. Mol Endocrinol. 1992 Sep;6(9):1451–1457. doi: 10.1210/mend.6.9.1435789. [DOI] [PubMed] [Google Scholar]
- Rao S. S., Chu C., Kohtz D. S. Ectopic expression of cyclin D1 prevents activation of gene transcription by myogenic basic helix-loop-helix regulators. Mol Cell Biol. 1994 Aug;14(8):5259–5267. doi: 10.1128/mcb.14.8.5259. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Renaud J. P., Rochel N., Ruff M., Vivat V., Chambon P., Gronemeyer H., Moras D. Crystal structure of the RAR-gamma ligand-binding domain bound to all-trans retinoic acid. Nature. 1995 Dec 14;378(6558):681–689. doi: 10.1038/378681a0. [DOI] [PubMed] [Google Scholar]
- Retnakaran R., Flock G., Giguère V. Identification of RVR, a novel orphan nuclear receptor that acts as a negative transcriptional regulator. Mol Endocrinol. 1994 Sep;8(9):1234–1244. doi: 10.1210/mend.8.9.7838156. [DOI] [PubMed] [Google Scholar]
- Rudnicki M. A., Schnegelsberg P. N., Stead R. H., Braun T., Arnold H. H., Jaenisch R. MyoD or Myf-5 is required for the formation of skeletal muscle. Cell. 1993 Dec 31;75(7):1351–1359. doi: 10.1016/0092-8674(93)90621-v. [DOI] [PubMed] [Google Scholar]
- Sadowski I., Ma J., Triezenberg S., Ptashne M. GAL4-VP16 is an unusually potent transcriptional activator. Nature. 1988 Oct 6;335(6190):563–564. doi: 10.1038/335563a0. [DOI] [PubMed] [Google Scholar]
- Sadowski I., Ptashne M. A vector for expressing GAL4(1-147) fusions in mammalian cells. Nucleic Acids Res. 1989 Sep 25;17(18):7539–7539. doi: 10.1093/nar/17.18.7539. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schneider J. W., Gu W., Zhu L., Mahdavi V., Nadal-Ginard B. Reversal of terminal differentiation mediated by p107 in Rb-/- muscle cells. Science. 1994 Jun 3;264(5164):1467–1471. doi: 10.1126/science.8197461. [DOI] [PubMed] [Google Scholar]
- Sherr C. J. G1 phase progression: cycling on cue. Cell. 1994 Nov 18;79(4):551–555. doi: 10.1016/0092-8674(94)90540-1. [DOI] [PubMed] [Google Scholar]
- Sherr C. J., Roberts J. M. Inhibitors of mammalian G1 cyclin-dependent kinases. Genes Dev. 1995 May 15;9(10):1149–1163. doi: 10.1101/gad.9.10.1149. [DOI] [PubMed] [Google Scholar]
- Sherr C. J. The ins and outs of RB: coupling gene expression to the cell cycle clock. Trends Cell Biol. 1994 Jan;4(1):15–18. doi: 10.1016/0962-8924(94)90033-7. [DOI] [PubMed] [Google Scholar]
- Skapek S. X., Rhee J., Spicer D. B., Lassar A. B. Inhibition of myogenic differentiation in proliferating myoblasts by cyclin D1-dependent kinase. Science. 1995 Feb 17;267(5200):1022–1024. doi: 10.1126/science.7863328. [DOI] [PubMed] [Google Scholar]
- Wagner R. L., Apriletti J. W., McGrath M. E., West B. L., Baxter J. D., Fletterick R. J. A structural role for hormone in the thyroid hormone receptor. Nature. 1995 Dec 14;378(6558):690–697. doi: 10.1038/378690a0. [DOI] [PubMed] [Google Scholar]
- Wurtz J. M., Bourguet W., Renaud J. P., Vivat V., Chambon P., Moras D., Gronemeyer H. A canonical structure for the ligand-binding domain of nuclear receptors. Nat Struct Biol. 1996 Jan;3(1):87–94. doi: 10.1038/nsb0196-87. [DOI] [PubMed] [Google Scholar]