Transcriptional Activation of the Enterocyte Differentiation Marker Intestinal Alkaline Phosphatase Is Associated With Changes in the Acetylation State of Histone H3 at a Specific Site Within Its Promoter Region In Vitro,

2003 ◽  
Vol 7 (2) ◽  
pp. 237-245 ◽  
Author(s):  
B Hinnebusch
Keyword(s):  
Alkaline Phosphatase ◽  
Transcriptional Activation ◽  
Promoter Region ◽  
Histone H3 ◽  
Specific Site ◽  
Intestinal Alkaline Phosphatase ◽  
Acetylation State ◽  
Differentiation Marker ◽  
Enterocyte Differentiation

A novel Sp1-relatedciselement involved in intestinal alkaline phosphatase gene transcription

1999 ◽  
Vol 276 (4) ◽  
pp. G800-G807 ◽  
Author(s):  
Jeong H. Kim ◽  
Shufen Meng ◽  
Amy Shei ◽  
Richard A. Hodin
Keyword(s):  
Alkaline Phosphatase ◽  
Transcriptional Activation ◽  
Molecular Mechanisms ◽  
Regulatory Element ◽  
Gene Activation ◽  
Regulatory Region ◽  
Intestinal Alkaline Phosphatase ◽  
Mobility Shift ◽  
Sv40 Promoter

We have used sodium butyrate-treated HT-29 cells as an in vitro model system to study the molecular mechanisms underlying intestinal alkaline phosphatase (IAP) gene activation. Transient transfection assays using human IAP-CAT reporter genes along with DNase I footprinting were used to localize a critical cis element (IF-III) corresponding to the sequence 5′-GACTGGGCGGGGTCAAGATGGA-3′. Deletion of the IF-III element resulted in a dramatic reduction in reporter gene activity, and IF-III was shown to function in the context of a heterologous (SV40) promoter in a cell type-specific manner, further supporting its functional role in IAP transactivation. Electrophoretic mobility shift assays revealed that IF-III binds Sp1 and Sp3, but these factors comprise only a portion of the total nuclear binding and appear to mediate only a small portion of its transcriptional activity. IF-III does not correspond to any previously characterized regulatory region from other intestine-specific genes. We have thus identified a novel, Sp1-related cis-regulatory element in the human IAP gene that appears to play a role in its transcriptional activation during differentiation in vitro.

scholarly journals Thyroid Hormone Positively Regulates the Enterocyte Differentiation Marker Intestinal Alkaline Phosphatase Gene via an Atypical Response Element

2004 ◽  
Vol 18 (8) ◽  
pp. 1941-1962 ◽  
Author(s):  
Madhu S. Malo ◽  
Wenying Zhang ◽  
Fuad Alkhoury ◽  
Premraj Pushpakaran ◽  
Mario A. Abedrapo ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Thyroid Hormone ◽  
Intestinal Alkaline Phosphatase ◽  
Response Element ◽  
Differentiation Marker ◽  
Enterocyte Differentiation

Enterocyte differentiation marker intestinal alkaline phosphatase is a target gene of the gut-enriched Krüppel-like factor

2004 ◽  
Vol 286 (1) ◽  
pp. G23-G30 ◽  
Author(s):  
Brian F. Hinnebusch ◽  
Aleem Siddique ◽  
J. Welles Henderson ◽  
Madhu S. Malo ◽  
Wenying Zhang ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Protein Interactions ◽  
Target Gene ◽  
Marker Gene ◽  
Luciferase Reporter ◽  
Intestinal Alkaline Phosphatase ◽  
Human Colon Cancer ◽  
Cis Element ◽  
Differentiation Marker ◽  
Enterocyte Differentiation

We have examined the role that the transcription factor gut-enriched Krüppel-like factor (KLF4 or GKLF) plays in activating the enterocyte differentiation marker gene intestinal alkaline phosphatase (IAP). A yeast one-hybrid screen was used to identify proteins interacting with a previously identified cis-element (IF-III) located within the human IAP gene promoter. DNA-protein interactions were determined by using EMSA. Northern blot analysis was used to study RNA expression in human colon cancer RKO cells engineered to overexpress KLF4. Transient transfections with IAP-luciferase reporter constructs were used to characterize the mechanisms by which KLF4 activates IAP transcription. The yeast one-hybrid screen and EMSA identified KLF4 as binding to IF-III. RKO cells induced to overexpress KLF4 demonstrated a corresponding dose-dependent increase in IAP expression, and EMSA with nuclear extract from these cells confirmed that KLF4 binds to the IF-III element. Transient transfections revealed that KLF4 transactivated the IAP gene largely via a critical segment in the IAP promoter that includes the IF-III cis-element. Mutant KLF4 constructs failed to fully activate IAP. We have identified the enterocyte differentiation marker IAP as a KLF4 target gene. IAP transactivation by KLF4 is likely mediated through a critical region located within the proximal IAP promoter region.

Intestinal alkaline phosphatase gene expression is activated by ZBP-89

2006 ◽  
Vol 290 (4) ◽  
pp. G737-G746 ◽  
Author(s):  
Madhu S. Malo ◽  
Moushumi Mozumder ◽  
Xiao Bo Zhang ◽  
Shaluk Biswas ◽  
Alexander Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alkaline Phosphatase ◽  
Transcription Factor ◽  
Fat Absorption ◽  
Rt Pcr ◽  
Intestinal Alkaline Phosphatase ◽  
Reporter Assays ◽  
Differentiation Marker ◽  
Ht 29 ◽  
Enterocyte Differentiation

Intestinal alkaline phosphatase (IAP) is an enterocyte differentiation marker that functions to limit fat absorption. Zinc finger binding protein-89 (ZBP-89) is a Kruppel-type transcription factor that appears to promote a differentiated phenotype in the intestinal epithelium. The purpose of this study was to investigate the regulation of IAP gene expression by ZBP-89. RT-PCR, quantitative real-time RT-PCR, Western blot analyses, and reporter assays were used to determine the regulation of IAP by ZBP-89 in HT-29 and Caco-2 colon cancer cells. ZBP-89 knockdown was achieved by specific short interfering (si)RNA. EMSA and chromatin immunoprecipitation (ChIP) were performed to examine the binding of ZBP-89 to the IAP promoter. The results of RT-PCR, quantitative real-time PCR, and Western blot analyses showed that ZBP-89 was expressed at low levels in Caco-2 and HT-29 cells, whereas IAP was minimally expressed and absent in these cells, respectively. Transfection with ZBP-89 expression plamid increased IAP mRNA and protein levels in both cell lines, whereas knockdown of endogenous ZBP-89 by siRNA reduced basal levels of IAP gene expression in Caco-2 cells. IAP-luciferase reporter assays, EMSA, and ChIP established that ZBP-89 activated the IAP gene through a response element (ZBP-89 response element: 5′-CCTCCTCCC-3′) located between −1018 and −1010 bp upstream of the AUG start codon. We conclude that ZBP-89 is a direct transcriptional activator of the enterocyte differentiation marker IAP. These findings are consistent with the role that this transcription factor is thought to play as a tumor suppressor and suggests its possible function in the physiology of fat absorption.

scholarly journals Peroxisome Proliferator-Activated Receptor-γ Antagonizes LOX-1-Mediated Endothelial Injury by Transcriptional Activation of miR-590-5p

PPAR Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Lei Xu ◽  
Gang Zhao ◽  
Hong Zhu ◽  
Shijun Wang ◽  
Aijun Sun ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transcriptional Activation ◽  
Promoter Region ◽  
Nuclear Translocation ◽  
Therapeutic Potential ◽  
Umbilical Vein ◽  
Density Lipoprotein ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is one of the major receptors expressed on the endothelium of arterial wall with a key role in endothelial dysfunction and the development of atherosclerosis. Recent evidence suggested that LOX-1 is upregulated under the condition of insulin resistance and could be suppressed by the antidiabetic drugs. We previously also confirmed that Thiazolidinedione (TZD) has the inhibitory effect on LOX-1 in ox-LDL-induced endothelial cells. However, the underlying mechanism is unclear. Here we showed that Rosiglitazone treatment significantly attenuated the expressions of LOX-1, ICAM-1, VCAM-1, p47phox, and the atherosclerotic lesions in ApoE-/- mice with high-fat diet. In vitro, we revealed that Rosiglitazone inhibited LOX-1 by regulating miR-590-5p. Ox-LDL-mediated ICAM-1, VCAM-1, and p47phox were significantly reduced by Rosiglitazone, but all reversed after pretreating the cells with antagomiR-590-5p. Induction with Rosiglitazone activated PPAR-γ and promoted its nuclear translocation in cultured human umbilical vein endothelial cells (HUVECs). The nuclear PPAR-γ upregulated the miR-590-5p level through binding to its transcriptional promoter region. Retaining PPAR-γ in cytoplasm by transfecting with PPAR-γ⊿NLS plasmid in HUVECs failed to activate miR-590-5p. Mutation of the promoter region of PPAR-γ also reduced the miR-590-5p promoter luciferase activity. Collectively, these data indicated that PPAR-γ may have the therapeutic potential in atherosclerosis via the transcriptional regulation of miR-590-5p in endothelial cells.

scholarly journals Drosophila Ada2b Is Required for Viability and Normal Histone H3 Acetylation

2004 ◽  
Vol 24 (18) ◽  
pp. 8080-8089 ◽  
Author(s):  
Dai Qi ◽  
Jan Larsson ◽  
Mattias Mannervik
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Protein Complexes ◽  
P53 Protein ◽  
Polytene Chromosomes ◽  
Histone H3 ◽  
Saga Complex ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

ABSTRACT Regulation of chromatin through histone acetylation is an important step in gene expression. The Gcn5 histone acetyltransferase is part of protein complexes, e.g., the SAGA complex, that interact with transcriptional activators, targeting the enzyme to specific promoters and assisting in recruitment of the basal RNA polymerase transcription machinery. The Ada2 protein directly binds to Gcn5 and stimulates its catalytic activity. Drosophila contains two Ada2 proteins, Drosophila Ada2a (dAda2a) and dAda2b. We have generated flies that lack dAda2b, which is part of a Drosophila SAGA-like complex. dAda2b is required for viability in Drosophila, and its deletion causes a reduction in histone H3 acetylation. A global hypoacetylation of chromatin was detected on polytene chromosomes in dAda2b mutants. This indicates that the dGcn5-dAda2b complex could have functions in addition to assisting in transcriptional activation through gene-specific acetylation. Although the Drosophila p53 protein was previously shown to interact with the SAGA-like complex in vitro, we find that p53 induction of reaper gene expression occurs normally in dAda2b mutants. Moreover, dAda2b mutant animals show excessive p53-dependent apoptosis in response to gamma radiation. Based on this result, we speculate that dAda2b may be necessary for efficient DNA repair or generation of a DNA damage signal. This could be an evolutionarily conserved function, since a yeast ada2 mutant is also sensitive to a genotoxic agent.

scholarly journals Identification of a novel distal enhancer in human adiponectin gene

2008 ◽  
Vol 200 (1) ◽  
pp. 107-116 ◽  
Author(s):  
Katsumori Segawa ◽  
Morihiro Matsuda ◽  
Atsunori Fukuhara ◽  
Kentaro Morita ◽  
Yosuke Okuno ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Promoter Region ◽  
Luciferase Activity ◽  
Proximal Region ◽  
Proximal Promoter ◽  
Luciferase Reporter ◽  
Adiponectin Gene ◽  
Distal Enhancer

Adiponectin is exclusively expressed in adipose tissue and secreted from adipocytes, and shows anti-diabetic and anti-atherogenic properties. However, the precise transcriptional mechanism of adiponectin remains elusive. In this study, the 5′ flanking promoter region of human adiponectin gene was analyzed using UCSC genome browser, and a 10 390-bp fragment, containing an evolutionally conserved region among species, was investigated. The luciferase reporter assay using this fragment identified a novel distal enhancer of human adiponectin gene. Promoter constructs with the distal enhancer exhibited high promoter activities in 3T3-L1 mature adipocytes. However, no such activity was observed in other types of cell lines. The distal enhancer is highly conserved, and contains two completely conserved CCAAT boxes. In 3T3-L1 mature adipocytes, deletion or each point mutation of these CCAAT boxes markedly reduced luciferase activity driven by adiponectin promoter. Knockdown of CCAAT/enhancer-binding protein α (CEBPA; also known as C/EBPα) using small interfering RNA diminished adiponectin mRNA expression and luciferase activity driven by adiponectin promoter with the distal enhancer. However, adiponectin promoter with each mutation of two CCAAT boxes in the distal enhancer did not respond to knockdown of CEBPA expression. Furthermore, CEBPA bound to the distal enhancer both in vitro and in vivo. We also identified a proximal promoter region responsible for transcriptional activation by the distal enhancer in human adiponectin gene. Our results indicate that CEBPA plays a pivotal role in the transcription of human adiponectin gene via the distal enhancer and proximal region in its promoter.

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