Volume 272, Number 29, Issue of July 18, 1997 pp. 18490-18497
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.

Two Distinct Factor-binding DNA Elements in Cardiac Myosin Light Chain 2 Gene Are Essential for Repression of Its Expression in Skeletal Muscle
ISOLATION OF A cDNA CLONE FOR REPRESSOR PROTEIN NISHED

(Received for publication, March 10, 1997, and in revised form, May 5, 1997)

From the Center for Cardiovascular and Muscle Research, Department of Anatomy and Cell Biology, State University of New York, Brooklyn, New York 11203

The expression of the cardiac myosin light chain 2 (MLC2) gene is repressed in skeletal muscle as a result of the negative regulation of its transcription. Two regulatory elements, the cardiac specific sequence (CSS) located upstream (360 base pairs) and a downstream negative modulatory sequence (NMS), which function in concert with each other, are required for repression of the MLC2 promoter activity in skeletal muscle. Individually, CSS and NMS have no effect. Transient transfection analysis with recombinant plasmids indicated that CSS- and NMS-mediated repression of transcription is position- and orientation-dependent and is transferable to heterologous promoters. A minimal conserved motif, GAAG/CTTC, present in both CSS and NMS, is responsible for repression as the mutation in the core CTTC sequence alone was sufficient to abrogate its repressor activity. The DNA binding assay by gel mobility shift analysis revealed that one of the two complexes, CSSBP2, is significantly enriched in embryonic skeletal muscle relative to cardiac muscle. In extracts from adult skeletal muscle, where the cardiac MLC2 expression is suppressed, both complexes, CSSBP1 and CSSBP2, were present, whereas the cardiac muscle extracts contained CSSBP1 alone, suggesting that the protein(s) in the CSSBP2 complex accounts for the negative regulation of cardiac MLC2 in skeletal muscle. A partial cDNA clone (Nished) specific for the candidate repressor factor was isolated by expression screening of the skeletal muscle cDNA library by multimerized CSS-DNA as probe. The recombinant Nished protein binds to the CSS-DNA, but not to CSS-DNA where the core CTTC sequence was mutated. The amino acid sequence of Nished showed a significant structural similarity to the sequence of transcription factor "runt," a known repressor of gap and pair-rule gene expression in Drosophila.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				J. L. Reyes-Juarez, R. Juarez-Rubi, G. Rodriguez, and A. Zarain-Herzberg Transcriptional Analysis of the Human Cardiac Calsequestrin Gene in Cardiac and Skeletal Myocytes J. Biol. Chem., December 7, 2007; 282(49): 35554 - 35563. [Abstract] [Full Text] [PDF]

				S. Mathew, E. Mascareno, and M. A. Q. Siddiqui A Ternary Complex of Transcription Factors, Nished and NFATc4, and Co-activator p300 Bound to an Intronic Sequence, Intronic Regulatory Element, Is Pivotal for the Up-regulation of Myosin Light Chain-2v Gene in Cardiac Hypertrophy J. Biol. Chem., September 24, 2004; 279(39): 41018 - 41027. [Abstract] [Full Text] [PDF]

				B. V. Latinkic, B. Cooper, S. Smith, S. Kotecha, N. Towers, D. Sparrow, and T. J. Mohun Transcriptional regulation of the cardiac-specific MLC2 gene during Xenopus embryonic development Development, February 1, 2004; 131(3): 669 - 679. [Abstract] [Full Text] [PDF]

				K. Esser, T. Nelson, V. Lupa-Kimball, and E. Blough The CACC Box and Myocyte Enhancer Factor-2 Sites within the Myosin Light Chain 2 Slow Promoter Cooperate in Regulating Nerve-specific Transcription in Skeletal Muscle J. Biol. Chem., April 23, 1999; 274(17): 12095 - 12102. [Abstract] [Full Text] [PDF]

				M. Gupta, R. Zak, T. A. Libermann, and M. P. Gupta Tissue-Restricted Expression of the Cardiac alpha -Myosin Heavy Chain Gene Is Controlled by a Downstream Repressor Element Containing a Palindrome of Two Ets-Binding Sites Mol. Cell. Biol., December 1, 1998; 18(12): 7243 - 7258. [Abstract] [Full Text]

				J. Song, H. Ugai, I. Kanazawa, K. Sun, and K. K. Yokoyama Independent Repression of a GC-rich Housekeeping Gene by Sp1 and MAZ Involves the Same cis-Elements J. Biol. Chem., June 1, 2001; 276(23): 19897 - 19904. [Abstract] [Full Text] [PDF]

				C. Terraz, D. Toman, M. Delauche, P. Ronco, and J. Rossert delta EF1 Binds to a Far Upstream Sequence of the Mouse Pro-alpha 1(I) Collagen Gene and Represses Its Expression in Osteoblasts J. Biol. Chem., September 28, 2001; 276(40): 37011 - 37019. [Abstract] [Full Text] [PDF]