AP2/ERF transcription factor is a kind of transcription factors widely existing in plants, and contains at least a conserved AP2/ERF domain composed of about 60-70 amino acids. AP2/ERF transcription factors are widely involved in a variety of physiological processes in plants, including plant development, fruit ripening, flower development and other plant development processes, as well as such stress response processes as damage, pathogen defense, high-salt condition and drought. In recent years, secondary metabolic engineering that takes transcription factors as genetic manipulation targets has developed rapidly in improving the content of active ingredients and the quality of medicinal plants. This paper reviews the recent progress in the regulation of secondary metabolites biosynthesis with AP2/ERF transcription factors, and provides theoretical basis for the exploration of efficient regulatory targets, the regulation of secondary metabolites in medicinal plants, the targeted improvement of the content of active ingredients in traditional Chinese medicine, and the sustainable supply of high-quality traditional Chinese medicines.
Gene Expression Regulation, Plant ; Phylogeny ; Plant Proteins/metabolism* ; Transcription Factor AP-2/metabolism* ; Transcription Factors/metabolism*

OBJECTIVETo evaluate the effect of low salt (LS) on the expression of cyclooxygenase-2 (COX-2) and the activity of nuclear factor kappa B (NF-kappaB) and activator protein-1 (AP-1) in the mouse macula densa derived (MMDD1) cell line.

METHODSMMDD1 cells were transfected with luciferase reporter plasmid containing AP-1 or NF-kappaB. Luciferase reporter assay was used to evaluate the effect of normal salt (NS) and low salt (LS) on the activities of NF-kappaB and AP-1. The changes of COX-2 expression were examined by RT-PCR. The expression of p-p38 MAPK, p-p44/42, c-Jun, c-Fos, and COX-2 in MMDD1 cells were analyzed by Western blot.

RESULTSThe expressions of COX-2 mRNA and protein in MMDD1 cells were significantly increased by LS (P < 0.01). Phosphorylated p38 and p44/42 MAP kinase were significantly increased by treatment at 180 min (P < 0.01). The up-regulated COX-2 protein expression with LS were significantly reduced with SB 203580 (p38 inhibitors) and PD-98059 (p44/42 inhibitors) (P < 0.01). The expressions of c-Jun and c-Fos were increased by LS. The luciferase activities of AP-1 and NF-kappaB were stimulated in LS (P < 0.01), the up-regulated luciferase activities were attenuated by PDTC at 25 micromol/L (NF-kappaB inhibitor) and curcumin at 20 micromol/L (AP-1 inhibitor) (P < 0.01). LS altered COX-2 mRNA abundance and protein expression were decreased in treatment with PDTC at 25 micromol/L, curcumin at 20 micromol/L (P < 0.01).

CONCLUSIONLS can induce the expression of COX-2 in MMDD1 cells, which may be involved in the activation of p38 MAP kinase, p44/42 kinase, AP-1, and NF-kappaB pathways.

Animals ; Cell Line ; Cyclooxygenase 2 ; metabolism ; Kidney ; cytology ; metabolism ; Mice ; NF-kappa B ; metabolism ; Signal Transduction ; Transcription Factor AP-1 ; metabolism

OBJECTIVETo investigate the effect of AP-1 Decoy on matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase (TIMP-1) imbalance induced by bleomycin-A5 (BLM-A5) in pulmonary fibroblasts.

METHODSPulmonary fibroblasts were primary cultured, and transferred with AP-1 Decoy before treated with BLM-A5. MMPs activity in medium was determined by gelatin zymography. Protein content of TIMP-1 in medium was detected by ELISA. Expression of MMP-2 mRNA and TIMP-1 mRNA were determined by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTSBLM-A5 induced the increase in activity of MMP-2 at 12 h [A: (0.77 +/- 0.08) vs (0.65 +/- 0.07) P < 0.05], but it was suppressed by AP-1 Decoy [A: (0.68 +/- 0.05)]. BLM-A5 up-regulated the expression of protein and mRNA of TIMP-1 after 12 h, and 24 h [(39.3 +/- 4.3), (46.3 +/- 4.8) ng/ml vs (28.9 +/- 2.7), (31.6 +/- 2.4) ng/ml] and [Absorbance ratio to beta-actin: (0.94 +/- 0.13, 1.08 +/- 0.06) vs (0.76 +/- 0.07, 0.75 +/- 0.08)] (P < 0.05 or P < 0.01) but AP-1 Decoy modulated the up-regulation. All these indexes in AP-1 Decoy group had no significant difference in contrast to the normal group. Mutant AP-1 Decoy had not the same function as AP-1 Decoy on the expression of MMP-2 and TIMP-1 in pulmonary fibroblasts.

CONCLUSIONAP-1 Decoy inhibits the increase in MMP-2 activity and the up-regulation of TIMP-1 induced by BLM-A5 in pulmonary fibroblasts.

Bleomycin ; analogs & derivatives ; pharmacology ; Fibroblasts ; drug effects ; metabolism ; Humans ; Lung ; cytology ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Pulmonary Fibrosis ; metabolism ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Transcription Factor AP-1 ; metabolism

Herpesvirus saimiri (HVS), a member of the gamma-herpesvirus family, encodes an oncoprotein called Saimiri Transforming Protein (STP) which is required for lymphoma induction in non-human primates. However, a detailed mechanism of STP-A11-induced oncogenesis has not been revealed yet. We first report that STP-A11 oncoprotein interacts with TNF-alpha receptor-associated factor (TRAF) 6 in vivo and in vitro. Mutagenesis analysis of the TRAF6-binding motif 10PQENDE15 in STP-A11 reveals that Glu (E)12 residue is critical for binding to TRAF6 and NF-kappaB activation. Interestingly, co-expression of E12A mutant, lack of TRAF6 binding, with cellular Src (Src) results in decreased transcriptional activity of Stat3 and AP-1, a novel target of STP-A11 compared to that of wild type. Furthermore, the presence of STP-A11 enhances the association of TRAF6 with Src and induces the translocation of both TRAF6 and Src to a nonionic detergent-insoluble fraction. Taken together, these studies suggest that STP-A11 oncoprotein up-regulates both NF-kappaB and AP-1 transcription activity through TRAF6, which would ultimately contribute cellular transformation.
*Transcription, Genetic ; Transcription Factor AP-1/agonists/*metabolism ; TNF Receptor-Associated Factor 6/*metabolism ; Solubility ; STAT3 Transcription Factor/metabolism ; Proto-Oncogene Proteins pp60(c-src)/metabolism ; Protein Binding ; Oncogene Proteins, Viral/*metabolism ; NF-kappa B/agonists/*metabolism ; Ions ; Humans ; Herpesvirus 2, Saimiriine/*metabolism ; Detergents ; Cell Line

OBJECTIVE: To explore the transcriptional regulation mechanism and biological function of low expression of vasoactive intestinal peptide receptor 1 (VIPR1) in hepatocellular carcinoma (HCC). METHODS: We constructed plasmids carrying wild-type VIPR1 promoter or two mutant VIPR1 promoter sequences for transfection of the HCC cell lines Hep3B and Huh7, and examined the effect of AP-2α expression on VIPR1 promoter activity using dual-luciferase reporter assay. Pyrosequencing was performed to detect the changes in VIPR1 promoter methylation level in HCC cells treated with a DNA methyltransferase inhibitor (DAC). Chromatin immunoprecipitation was used to evaluate the binding ability of AP-2α to VIPR1 promoter. Western blotting was used to assess the effect of AP-2α knockdown on VIPR1 expression and examine the differential expression of VIPR1 in the two cell lines. The effects of VIPR1 overexpression and knockdown on the proliferation, cell cycle and apoptosis of HCC cells were analyzed using CCK8 assay and flow cytometry. We also observed the growth of HCC xenograft with lentivirus-mediated over-expression of VIPR1 in nude mice. RESULTS: Compared with the wild-type VIPR1 promoter group, co-transfection with the vector carrying two promoter mutations and the AP-2α-over-expressing plasmid obviously restored the luciferase activity in HCC cells (P < 0.05). DAC treatment of the cells significantly decreased the methylation level of VIPR1 promoter and inhibited the binding of AP-2α to VIPR1 promoter (P < 0.01). The HCC cells with AP-2α knockdown showed increased VIPR1 expression, which was lower in Huh7 cells than in Hep3B cells. VIPR1 overexpression in HCC cells caused significant cell cycle arrest in G2/M phase (P < 0.01), promoted cell apoptosis (P < 0.001), and inhibited cell proliferation (P < 0.001), while VIPR1 knockdown produced the opposite effects. In the tumor-bearing nude mice, VIPR1 overexpression in the HCC cells significantly suppressed the increase of tumor volume (P < 0.001) and weight (P < 0.05). CONCLUSION VIPR1 promoter methylation in HCC promotes the binding of AP-2α and inhibits VIPR1 expression, while VIPR1 overexpression causes cell cycle arrest, promotes cell apoptosis, and inhibits cell proliferation and tumor growth.
Animals ; Carcinoma, Hepatocellular/pathology* ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic ; Humans ; Liver Neoplasms/pathology* ; Luciferases/genetics* ; Methylation ; Mice ; Mice, Nude ; Receptors, Vasoactive Intestinal Polypeptide, Type I/metabolism* ; Transcription Factor AP-2/metabolism*

OBJECTIVETo construct a luciferase reporter vector containing the response element of transcription protein AP2α for screening the effect of bone morphogenetic proteins (BMPs) on the transcriptional activity of AP2α.

METHODSFour tandem-linked response elements of AP2α were cloned to the pBGLuc luciferase reporter gene plasmid, which was digested with Bam HI and Mlu I to construct pBGLuc-AP2α-RE vector. The recombinant adenovirus Ad-AP2α and its dominant negative mutant Ad-dnAP2α were used to infect mouse mesenchymal stem cells C3H10; the changes in cellular AP2α mRNA and protein expressions were detected by real-time PCR and Western blotting, and electrophoretic mobility shift assay (EMSA) was carried out to assess the DNA-binding ability of AP2α. C3H10 cells were transfected with pBGLuc-AP2α-RE vector, and AP2α transcriptional activity was measured using luciferase reporter gene assay. In pBGLuc-AP2α-RE vector-transfected C3H10 cells infected with Ad-BMPs, luciferase reporter gene assay was performed to screen the effect of BMPs on AP2α transcriptional activity.

RESULTSThe results of PCR, enzyme digestion and sequencing all confirmed correct cloning of AP2α-RE into pBGLuc-AP2α-RE luciferase reporter vector, and Ad-AP2α infection significantly increased AP2α expression and its DNA binding ability. The dominant negative mutants expressed the corresponding mutants, and EMSA results showed that Ad-dnAP2α-δbHLH significantly lowered while Ad-dnAP2α-δTAD enhanced the DNA-binding ability of AP2α. AP2α over-expression promoted AP2α transcriptional activity, which was suppressed by the two dominant negative mutants. AP2α transcriptional activity increased in the cells infected with the recombinant adenovirus BMPs, especially in cells with BMP9 infection.

CONCLUSIONSThe luciferase reporter vector containing the response element of AP2α we constructed allows detection of AP2α transcriptional activity. BMP9 can significantly enhance AP2α transcriptional activity.

Adenoviridae ; Animals ; Bone Morphogenetic Proteins ; genetics ; metabolism ; Genes, Reporter ; Genetic Vectors ; Growth Differentiation Factor 2 ; genetics ; metabolism ; Luciferases ; genetics ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Mice ; Osteogenesis ; Protein Binding ; RNA, Messenger ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; Response Elements ; Transcription Factor AP-2 ; genetics ; metabolism ; Transcriptional Activation ; Transfection

OBJECTIVETo investigate whether the decrease in expression of interleukin-2 (IL-2) after trauma is associated with changes in DNA binding activity of nuclear factor of activated T cells (NFAT) and activator protein-1 (AP-1).

METHODSMice with closed impact injury with fracture in both hind limbs were adopted as the trauma model. Spleen lymphocytes were isolated from traumatized mice and stimulated with Con-A. Culture supernatants were assayed for IL-2 activity, and total RNA was extracted from spleen lymphocytes and assayed for IL-2 mRNA. DNA binding activity of NFAT and AP-1 were measured by electrophoretic mobility shift assay (EMSA). The expression of c-Fos, c-Jun and JunB proteins was determined by the Western blot analysis.

RESULTSDNA binding activity of NFAT and AP-1 gradually decreased to a minimum of 41% and 49%, respectively, of the control on the 4th day after injury, which was closely followed by the decline in IL-2 activity and IL-2 mRNA. A decrease in the expression of c-Fos on the 1st and 4th day after trauma had no significant effect on c-Jun expression; the increase in expression of JunB was only on the 1st day after injury.

CONCLUSIONDecreased IL-2 expression is, at least in part, due to a decline in the activation of NFAT and AP-1 in traumatized mice. The decline in DNA binding activity of NFAT and AP-1 is partly due to a trauma-induced block in the expression of c-Fos.

Animals ; Cell Nucleus ; chemistry ; DNA ; metabolism ; DNA-Binding Proteins ; metabolism ; Electrophoretic Mobility Shift Assay ; Female ; Interleukin-2 ; analysis ; genetics ; Male ; Mice ; NFATC Transcription Factors ; Nuclear Proteins ; Proto-Oncogene Proteins c-fos ; analysis ; Proto-Oncogene Proteins c-jun ; analysis ; RNA, Messenger ; analysis ; Transcription Factor AP-1 ; metabolism ; Transcription Factors ; metabolism

Toxic effects of ozone, 4-(N-methyl-N-nitrosamino)-1-(3- pyridyl)-1-butanone (NNK), and/or dibutyl phthalate (DBP) were examined through NF-kappaB, AP-1, Nrf2, and osteopontin (OPN) in lungs and livers of B6C3F1 mice. Electrophoretic mobility shift assay (EMSA) indicated that mice treated with combination of toxicants induced high NF-kappaB activities. Expression levels of p105, p65, and p50 proteins increased in all treated mice, whereas IkB activity was inhibited in NNK-, DBP-, and combination-treated ones. All treated mice except ozone-treated one showed high AP-1 binding activities. Expression levels of c-fos, c-jun, junB, jun D, Nrf2, and OPN proteins increased in all treated mice. Additive interactions were frequently noted from two-toxicant combination mice compared to ozone-treated one. These results indicate treatment of mixture of toxicants increased toxicity through NF-kappaB, AP-1, Nrf2, and OPN. Our data could be applied to the elucidation of mechanism as well as the risk assessment of mixture-induced toxicity.
Animals ; Blotting, Western ; DNA-Binding Proteins/*metabolism ; Dibutyl Phthalate/*toxicity ; Electrophoretic Mobility Shift Assay ; Kidney/*drug effects/metabolism ; Liver/*drug effects/metabolism ; Mice ; Mice, Inbred Strains ; NF-E2-Related Factor 2 ; NF-kappa B/metabolism ; Nitrosamines/*toxicity ; Osteopontin ; Ozone/*toxicity ; Proto-Oncogene Proteins/metabolism ; Risk Assessment ; Sialoglycoproteins/*metabolism ; Trans-Activators/metabolism ; Transcription Factor AP-1/metabolism

ERF family transcription factor (TF) represented ethylene-responsive protein which harbored a conserved AP2 domain. After searching the plant transcription factor database, a total of 75 unigenes was found which contained AP2 domain from the transcriptome dataset of Panax quinquefolius L. One unique sequence of ERF transcript, named as PqERF1, was cloned with entire open reading frame of 933 base pairs (bp). Protein prediction result indicated that the gene was localized in nucleus and had a conserved AP2 domain. PqERF1 gene could be induced by methyl jasmonate (MeJA) which was consistent to the inducing profile of triterpene ginsenosides. InterproScan prediction indicated that PqERF1 was probably a pathogenesis-related gene. Sequence alignment and phylogenetic analysis demonstrated PqERF1 was with high identity and had relative close relationship to the NtERF4 (Nicotiana tabacum), PhERF12 (Petunia x hybrida) and DcERF1 (Daucus carota) which was related to plant defense, regulation of secondary metabolism and the flower senescence respectively. Therefore, the gene was likely involved in regulation of secondary metabolism, plant defense and physical processes which would provide gene resource for further study on secondary metabolite synthesis and molecular breeding of P. quinquefolius.
Amino Acid Sequence ; Computational Biology ; Daucus carota ; genetics ; metabolism ; Gene Expression Regulation, Plant ; Open Reading Frames ; Panax ; genetics ; metabolism ; Petunia ; genetics ; metabolism ; Phylogeny ; Plant Proteins ; genetics ; metabolism ; Protein Structure, Secondary ; RNA, Plant ; genetics ; Sequence Alignment ; Tobacco ; genetics ; metabolism ; Transcription Factor AP-2 ; genetics ; metabolism

Stimulatory heterotrimeric GTP-binding proteins (Gs protein) stimulate cAMP generation in response to various signals, and modulate various cellular phenomena such as proliferation and apoptosis. This study aimed to investigate the effect of Gs proteins on gamma ray-induced apoptosis of lung cancer cells and its molecular mechanism, as an attempt to develop a new strategy to improve the therapeutic efficacy of gamma radiation. Expression of constitutively active mutant of the alpha subunit of Gs (GalphasQL) augmented gamma ray-induced apoptosis via mitochondrial dependent pathway when assessed by clonogenic assay, FACS analysis of PI stained cells, and western blot analysis of the cytoplasmic translocation of cytochrome C and the cleavage of caspase-3 and ploy(ADP-ribose) polymerase (PARP) in H1299 human lung cancer cells. GalphasQL up-regulated the Bak expression at the levels of protein and mRNA. Treatment with inhibitors of PKA (H89), SP600125 (JNK inhibitor), and a CRE-decoy blocked GalphasQL-stimulated Bak reporter luciferase activity. Expression of GalphasQL increased basal and gamma ray-induced luciferase activity of cAMP response element binding protein (CREB) and AP-1, and the binding of CREB and AP-1 to Bak promoter. Furthermore, prostaglandin E2, a Galphas activating signal, was found to augment gamma ray-induced apoptosis, which was abolished by treatment with a prostanoid receptor antagonist. These results indicate that Galphas augments gamma ray-induced apoptosis by up-regulation of Bak expression via CREB and AP-1 in H1299 lung cancer cells, suggesting that the efficacy of radiotherapy of lung cancer may be improved by modulating Gs signaling pathway.
Apoptosis/*radiation effects ; Cell Line, Tumor ; Cyclic AMP Response Element-Binding Protein/metabolism ; GTP-Binding Protein alpha Subunits, Gs/*metabolism ; *Gamma Rays ; Heterotrimeric GTP-Binding Proteins/metabolism ; Humans ; Lung/*cytology/physiology/radiation effects ; Lung Neoplasms ; Transcription Factor AP-1/metabolism ; *Up-Regulation ; bcl-2 Homologous Antagonist-Killer Protein/*metabolism