This Article Full Text Full Text (PDF) All Versions of this Article: 97/10/983    most recent 01.RES.0000190604.90049.71v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Qiu, P. Articles by Li, L. Search for Related Content PubMed PubMed Citation Articles by Qiu, P. Articles by Li, L. Pubmed/NCBI databases Gene GEO Profiles HomoloGene UniGene Substance via MeSH Related Collections Developmental biology Gene regulation Growth factors/cytokines Smooth muscle proliferation and differentiation

(Circulation Research. 2005;97:983.)
© 2005 American Heart Association, Inc.

Molecular Medicine

Myocardin Enhances Smad3-Mediated Transforming Growth Factor-ß₁ Signaling in a CArG Box-Independent Manner

Smad-Binding Element Is an Important cis Element for SM22 Transcription In Vivo

Ping Qiu^*, Raquel P. Ritchie^*, Zhiyao Fu, Dongsun Cao, Jerry Cumming, Joseph M. Miano, Da-Zhi Wang, Hui J. Li, Li Li

From the Department of Internal Medicine (P.Q., R.R., Z.F., J.C., L.L.) and Center for Molecular Medicine and Genetics (P.Q., R.R., L.L.), Wayne State University, Detroit, Mich; Carolina Cardiovascular Biology Center (D.C., D.-Z.W.), Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill; Center for Cardiovascular Research in the Aab Institute of Biomedical Sciences (J.M.M.), University of Rochester School of Medicine, New York; and the Molecular Cardiology Research Institute (H.J.L.), Tufts University School of Medicine, Boston, Mass.

Correspondence to Li Li, 421 E Canfield Ave, #1107, Detroit, MI 48201. E-mail lili{at}med.wayne.edu

Transforming growth factor (TGF)-ß₁ is an important cytokine involved in various diseases. However, the molecular mechanism whereby TGF-ß₁ signaling modulates the regulatory network for smooth muscle gene transcription remains largely unknown. To address this question, we previously identified a Smad-binding element (SBE) in the SM22 promoter as one of the TGF-ß₁ response elements. Here, we show that mutation of the SBE reduces the activation potential of a SM22 promoter in transgenic mice during embryogenesis. Chromatin immunoprecipitation assays reveal that TGF-ß₁ induces Smad3 binding to the SM22 promoter in vivo. A multimerized SBE promoter responsive to TGF-ß₁ signaling is highly activated by Smad3 but not by the closely related Smad2. Intriguingly, myocardin (Myocd), a known CArG box-dependent serum response factor coactivator, participates in Smad3-mediated TGF-ß₁ signaling and synergistically stimulates Smad3-induced SBE promoter activity independent of the CArG box; no such synergy is seen with Smad2. Importantly, Myocd cooperates with Smad3 to activate the wild-type SM22, SM myosin heavy chain, and SM-actin promoters; they also activate the CArG box-mutated SM22 promoter as well as the CArG box-independent aortic carboxypeptidase-like protein promoter. Immunopreciptiation assays reveal that Myocd and Smad3 directly interact both in vitro and in vivo. Mutagenesis studies indicate that the C-terminal transactivation domains of Myocd and Smad3 are required for their functional synergy. These results reveal a novel regulatory mechanism whereby Myocd participates in TGF-ß₁ signal pathway through direct interaction with Smad3, which binds to the SBEs. This is the first demonstration that Myocd can act as a transcriptional coactivator of the smooth muscle regulatory network in a CArG box-independent manner.

Key Words: myocardin • SM22 or transgelin • Smad-binding site (SBE) • Smad3 • transforming growth factor-ß₁ • smooth muscle transcription

This article has been cited by other articles:

				H. J. Kim, M. Y. Kim, H. Jin, H. J. Kim, S. S. Kang, H. J. Kim, J. H. Lee, K. C. Chang, J.-Y. Hwang, C. Yabe-Nishimura, et al. Peroxisome Proliferator-Activated Receptor {delta} Regulates Extracellular Matrix and Apoptosis of Vascular Smooth Muscle Cells Through the Activation of Transforming Growth Factor-{beta}1/Smad3 Circ. Res., July 2, 2009; 105(1): 16 - 24. [Abstract] [Full Text] [PDF]

				K. Kawai-Kowase, T. Ohshima, H. Matsui, T. Tanaka, T. Shimizu, T. Iso, M. Arai, G. K. Owens, and M. Kurabayashi PIAS1 Mediates TGF{beta}-Induced SM {alpha}-Actin Gene Expression Through Inhibition of KLF4 Function-Expression by Protein Sumoylation Arterioscler Thromb Vasc Biol, January 1, 2009; 29(1): 99 - 106. [Abstract] [Full Text] [PDF]

				J. A. Lemmon and B. R. Wamhoff "FRNKly, Smooth Muscle, I Don't Give a CArG!": A Novel Mechanism for Smooth Muscle Cell Differentiation Arterioscler Thromb Vasc Biol, December 1, 2008; 28(12): 2091 - 2093. [Full Text] [PDF]

				R. L. Sayers, L. J. Sundberg-Smith, M. Rojas, H. Hayasaka, J. T. Parsons, C. P. Mack, and J. M. Taylor FRNK Expression Promotes Smooth Muscle Cell Maturation During Vascular Development and After Vascular Injury Arterioscler Thromb Vasc Biol, December 1, 2008; 28(12): 2115 - 2122. [Abstract] [Full Text] [PDF]

				K. Vaahtomeri, E. Ventela, K. Laajanen, P. Katajisto, P.-J. Wipff, B. Hinz, T. Vallenius, M. Tiainen, and T. P. Makela Lkb1 is required for TGF{beta}-mediated myofibroblast differentiation J. Cell Sci., November 1, 2008; 121(21): 3531 - 3540. [Abstract] [Full Text] [PDF]

				X. Long, R. D. Bell, W. T. Gerthoffer, B. V. Zlokovic, and J. M. Miano Myocardin Is Sufficient for a Smooth Muscle-Like Contractile Phenotype Arterioscler Thromb Vasc Biol, August 1, 2008; 28(8): 1505 - 1510. [Abstract] [Full Text] [PDF]

				K. Iwasaki, K. Hayashi, T. Fujioka, and K. Sobue Rho/Rho-associated Kinase Signal Regulates Myogenic Differentiation via Myocardin-related Transcription Factor-A/Smad-dependent Transcription of the Id3 Gene J. Biol. Chem., July 25, 2008; 283(30): 21230 - 21241. [Abstract] [Full Text] [PDF]

				G. Elberg, L. Chen, D. Elberg, M. D. Chan, C. J. Logan, and M. A. Turman MKL1 mediates TGF-{beta}1-induced {alpha}-smooth muscle actin expression in human renal epithelial cells Am J Physiol Renal Physiol, May 1, 2008; 294(5): F1116 - F1128. [Abstract] [Full Text] [PDF]

				S. Kennard, H. Liu, and B. Lilly Transforming Growth Factor- (TGF- 1) Down-regulates Notch3 in Fibroblasts to Promote Smooth Muscle Gene Expression J. Biol. Chem., January 18, 2008; 283(3): 1324 - 1333. [Abstract] [Full Text] [PDF]

				G. Lagna, M. M. Ku, P. H. Nguyen, N. A. Neuman, B. N. Davis, and A. Hata Control of Phenotypic Plasticity of Smooth Muscle Cells by Bone Morphogenetic Protein Signaling through the Myocardin-related Transcription Factors J. Biol. Chem., December 21, 2007; 282(51): 37244 - 37255. [Abstract] [Full Text] [PDF]

				T. Morita, T. Mayanagi, and K. Sobue Dual roles of myocardin-related transcription factors in epithelial mesenchymal transition via slug induction and actin remodeling J. Cell Biol., December 3, 2007; 179(5): 1027 - 1042. [Abstract] [Full Text] [PDF]

				L. Fan, A. Sebe, Z. Peterfi, A. Masszi, A. C.P. Thirone, O. D. Rotstein, H. Nakano, C. A. McCulloch, K. Szaszi, I. Mucsi, et al. Cell Contact-dependent Regulation of Epithelial-Myofibroblast Transition via the Rho-Rho Kinase-Phospho-Myosin Pathway Mol. Biol. Cell, March 1, 2007; 18(3): 1083 - 1097. [Abstract] [Full Text] [PDF]

				Y. Sheffer, O. Leon, J. H. Pinthus, A. Nagler, Y. Mor, O. Genin, M. Iluz, N. Kawada, K. Yoshizato, and M. Pines Inhibition of fibroblast to myofibroblast transition by halofuginone contributes to the chemotherapy-mediated antitumoral effect Mol. Cancer Ther., February 1, 2007; 6(2): 570 - 577. [Abstract] [Full Text] [PDF]

				K. Kawai-Kowase and G. K. Owens Multiple repressor pathways contribute to phenotypic switching of vascular smooth muscle cells Am J Physiol Cell Physiol, January 1, 2007; 292(1): C59 - C69. [Abstract] [Full Text] [PDF]

				K. Hayashi, S. Nakamura, W. Nishida, and K. Sobue Bone Morphogenetic Protein-Induced Msx1 and Msx2 Inhibit Myocardin-Dependent Smooth Muscle Gene Transcription Mol. Cell. Biol., December 15, 2006; 26(24): 9456 - 9470. [Abstract] [Full Text] [PDF]

				E. S. Jeon, H. J. Moon, M. J. Lee, H. Y. Song, Y. M. Kim, Y. C. Bae, J. S. Jung, and J. H. Kim Sphingosylphosphorylcholine induces differentiation of human mesenchymal stem cells into smooth-muscle-like cells through a TGF-{beta}-dependent mechanism J. Cell Sci., December 1, 2006; 119(23): 4994 - 5005. [Abstract] [Full Text] [PDF]

				G.C. T. Pipes, E. E. Creemers, and E. N. Olson The myocardin family of transcriptional coactivators: versatile regulators of cell growth, migration, and myogenesis. Genes & Dev., June 15, 2006; 20(12): 1545 - 1556. [Abstract] [Full Text] [PDF]

				T. E. Callis, D. Cao, and D.-Z. Wang Bone Morphogenetic Protein Signaling Modulates Myocardin Transactivation of Cardiac Genes Circ. Res., November 11, 2005; 97(10): 992 - 1000. [Abstract] [Full Text] [PDF]