scholarly journals Transcription factor GATA-4 regulates cardiac muscle-specific expression of the alpha-myosin heavy-chain gene.

1994 ◽  
Vol 14 (7) ◽  
pp. 4947-4957 ◽  
Author(s):  
J D Molkentin ◽  
D V Kalvakolanu ◽  
B E Markham

The alpha-myosin heavy-chain (alpha-MHC) gene is the major structural protein in the adult rodent myocardium. Its expression is restricted to the heart by a complex interplay of trans-acting factors and their cis-acting sites. However, to date, the factors that have been shown to regulate expression of this gene have also been found in skeletal muscle cells. Recently, transcription factor GATA-4, which has a tissue distribution limited to the heart and endodermally derived tissues, was identified. We recently found two putative GATA-binding sites within the proximal enhancer of the alpha-MHC gene, suggesting that GATA-4 might regulate its expression. In this study, we establish that GATA-4 interacts with the alpha-MHC GATA sites to stimulate cardiac muscle-specific expression. Mutation of the GATA-4-binding sites either individually or together decreased activity by 50 and 88% in the adult myocardium, respectively. GATA-4-dependent enhancement of activity from a heterologous promoter was mediated through the alpha-MHC GATA sites. Coinjection of an alpha-MHC promoter construct with a GATA-4 expression vector permitted ectopic expression in skeletal muscle but not in fibroblasts. Thus, the lack of alpha-MHC expression in skeletal muscle correlates with a lack of GATA-4. GATA-4 DNA binding activity was significantly up-regulated in triiodothyronine- or retinoic acid-treated cardiomyocytes. Putative GATA-4-binding sites are also found in the regulatory regions of other cardiac muscle-expressed structural genes. This indicates a mechanism whereby triiodothyronine and retinoic acid can exert coordinate control of the cardiac phenotype through a trans-acting regulatory factor.

1994 ◽  
Vol 14 (7) ◽  
pp. 4947-4957
Author(s):  
J D Molkentin ◽  
D V Kalvakolanu ◽  
B E Markham

The alpha-myosin heavy-chain (alpha-MHC) gene is the major structural protein in the adult rodent myocardium. Its expression is restricted to the heart by a complex interplay of trans-acting factors and their cis-acting sites. However, to date, the factors that have been shown to regulate expression of this gene have also been found in skeletal muscle cells. Recently, transcription factor GATA-4, which has a tissue distribution limited to the heart and endodermally derived tissues, was identified. We recently found two putative GATA-binding sites within the proximal enhancer of the alpha-MHC gene, suggesting that GATA-4 might regulate its expression. In this study, we establish that GATA-4 interacts with the alpha-MHC GATA sites to stimulate cardiac muscle-specific expression. Mutation of the GATA-4-binding sites either individually or together decreased activity by 50 and 88% in the adult myocardium, respectively. GATA-4-dependent enhancement of activity from a heterologous promoter was mediated through the alpha-MHC GATA sites. Coinjection of an alpha-MHC promoter construct with a GATA-4 expression vector permitted ectopic expression in skeletal muscle but not in fibroblasts. Thus, the lack of alpha-MHC expression in skeletal muscle correlates with a lack of GATA-4. GATA-4 DNA binding activity was significantly up-regulated in triiodothyronine- or retinoic acid-treated cardiomyocytes. Putative GATA-4-binding sites are also found in the regulatory regions of other cardiac muscle-expressed structural genes. This indicates a mechanism whereby triiodothyronine and retinoic acid can exert coordinate control of the cardiac phenotype through a trans-acting regulatory factor.


1998 ◽  
Vol 18 (12) ◽  
pp. 7243-7258 ◽  
Author(s):  
Madhu Gupta ◽  
Radovan Zak ◽  
Towia A. Libermann ◽  
Mahesh P. Gupta

ABSTRACT The expression of the α-myosin heavy chain (MHC) gene is restricted primarily to cardiac myocytes. To date, several positive regulatory elements and their binding factors involved in α-MHC gene regulation have been identified; however, the mechanism restricting the expression of this gene to cardiac myocytes has yet to be elucidated. In this study, we have identified by using sequential deletion mutants of the rat cardiac α-MHC gene a 30-bp purine-rich negative regulatory (PNR) element located in the first intronic region that appeared to be essential for the tissue-specific expression of the α-MHC gene. Removal of this element alone elevated (20- to 30-fold) the expression of the α-MHC gene in cardiac myocyte cultures and in heart muscle directly injected with plasmid DNA. Surprisingly, this deletion also allowed a significant expression of the α-MHC gene in HeLa and other nonmuscle cells, where it is normally inactive. The PNR element required upstream sequences of the α-MHC gene for negative gene regulation. By DNase I footprint analysis of the PNR element, a palindrome of two high-affinity Ets-binding sites (CTTCCCTGGAAG) was identified. Furthermore, by analyses of site-specific base-pair mutation, mobility gel shift competition, and UV cross-linking, two different Ets-like proteins from cardiac and HeLa cell nuclear extracts were found to bind to the PNR motif. Moreover, the activity of the PNR-binding factor was found to be increased two- to threefold in adult rat hearts subjected to pressure overload hypertrophy, where the α-MHC gene is usually suppressed. These data demonstrate that the PNR element plays a dual role, both downregulating the expression of the α-MHC gene in cardiac myocytes and silencing the muscle gene activity in nonmuscle cells. Similar palindromic Ets-binding motifs are found conserved in the α-MHC genes from different species and in other cardiac myocyte-restricted genes. These results are the first to reveal a role of the Ets class of proteins in controlling the tissue-specific expression of a cardiac muscle gene.


2014 ◽  
Vol 13 (4) ◽  
pp. 10231-10240 ◽  
Author(s):  
X.E. Shi ◽  
Z.Y. Song ◽  
Q.M. Yang ◽  
Y.G. Liu ◽  
G.S. Yang

2001 ◽  
Vol 21 (19) ◽  
pp. 6418-6428 ◽  
Author(s):  
Shelley Lane ◽  
Song Zhou ◽  
Ting Pan ◽  
Qian Dai ◽  
Haoping Liu

ABSTRACT Candida albicans undergoes a morphogenetic switch from budding yeast to hyphal growth form in response to a variety of stimuli and growth conditions. Multiple signaling pathways, including a Cph1-mediated mitogen-activated protein kinase pathway and an Efg1-mediated cyclic AMP/protein kinase A pathway, regulate the transition. Here we report the identification of a basic helix-loop-helix transcription factor of the Myc subfamily (Cph2) by its ability to promote pseudohyphal growth inSaccharomyces cerevisiae. Like sterol response element binding protein 1, Cph2 has a Tyr instead of a conserved Arg in the basic DNA binding region. Cph2 regulates hyphal development in C. albicans, ascph2/cph2 mutant strains show medium-specific impairment in hyphal development and in the induction of hypha-specific genes. However, many hypha-specific genes do not have potential Cph2 binding sites in their upstream regions. Interestingly, upstream sequences of all known hypha-specific genes are found to contain potential binding sites for Tec1, a regulator of hyphal development. Northern analysis shows that TEC1 transcription is highest in the medium in which cph2/cph2 displays a defect in hyphal development, and Cph2 is necessary for this transcriptional induction of TEC1. In vitro gel mobility shift experiments show that Cph2 directly binds to the two sterol regulatory element 1-like elements upstream of TEC1. Furthermore, the ectopic expression of TEC1 suppresses the defect ofcph2/cph2 in hyphal development. Therefore, the function of Cph2 in hyphal transcription is mediated, in part, through Tec1. We further show that this function of Cph2 is independent of the Cph1- and Efg1-mediated pathways.


1998 ◽  
Vol 75 (2) ◽  
pp. 135-147 ◽  
Author(s):  
Kotaro Yoshimura ◽  
William M. Kuzon ◽  
Kiyonori Harii

2003 ◽  
Vol 86 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Teet Seene ◽  
Priit Kaasik ◽  
Ando Pehme ◽  
Karin Alev ◽  
Eva-Maria Riso

PLoS ONE ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. e29082 ◽  
Author(s):  
Sharon L. Rowan ◽  
Karolina Rygiel ◽  
Fennigje M. Purves-Smith ◽  
Nathan M. Solbak ◽  
Douglas M. Turnbull ◽  
...  

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