HDAC1-Smad3-mSin3A complex is required for Smad3-induced transcriptional inhibition of hepatocyte growth factor receptor in human lung cancers.

c-Met hyperactivity has been observed in numerous neoplasms. Several researchers have shown that the abnormal activation of c-Met is mainly caused by transcriptional activation. However, the molecular mechanism behind this transcriptional regulation is poorly understood. Here, we suggest that Smad3 negatively regulates the expression and activation of c-Met via a transcriptional mechanism. We explore the molecular mechanisms that underlie Smad3-induced c-Met transcription inhibition. We found in contrast to the high expression of c-Met, Smad3 showed low protein and mRNA levels. Smad3 and c-Met expressions were inconsistent between lung cancer tissues and cell lines. We also found that Smad3 overexpression suppresses whereas Smad3 knockdown significantly promotes Epithelial-Mesenchymal Transition and production of the angiogenic factors VEGF, CTGF and COX-2 through the ERK1/2 pathway. In addition, Smad3 overexpression decreases whereas Smad3 knockdown significantly increases protein and mRNA levels of invasion-related ß-catenin and FAK through the PI3K/Akt pathway. Furthermore, using the chromatin immunoprecipitation analysis method, we demonstrate that a transcriptional regulatory complex consisting of HDAC1, Smad3 and mSin3A binds to the promoter of the c-Met gene. By either silencing endogenous mSin3A expression with siRNA or by pretreating cells with a specific HDAC1 inhibitor (MS-275), Smad3-induced transcriptional suppression of c-Met could be effectively attenuated. These results demonstrate that Smad3-induced inhibition of c-Met transcription depends on of a functional transcriptional regulatory complex that includes Smad3, mSin3A and HDAC1 at the c-Met promoter. Collectively, our findings reveal a new regulatory mechanism of c-Met signaling, and suggest a potential molecular target for the development of anticancer drugs.

Ectopic expression of BraYAB1-702, a member of YABBY gene family in Chinese cabbage, causes leaf curling, inhibition of development of shoot apical meristem and flowering stage delaying in Arabidopsis thaliana.

YABBY gene family plays an important role in the polarity development of lateral organs. We isolated the BraYAB1-702 gene, a member of the YABBY gene family, from young leaves of Chinese cabbage line 06J45. The full-length gene has a 937 bp CDNA sequence and contains an open reading frame (ORF) of 702 bp. The subcellular localization analysis showed that the expression product of the gene was localized in the nucleus. Ectopic expression of BraYAB1-702 in Arabidopsis thaliana caused leaf curling from the adaxial epidermises to abaxial epidermises; the partial abaxialization of the adaxial epidermises of leaves; leaf trichomes and stomata numbers being significantly increased; the plants being severely stunted; the flowering stage being remarkably delayed and inhibiting the development of shoot apical meristem (SAM) with the down-regulation of the expression of SHOOT MERISTEMLESS (STM), Brevipedicellus (BP) and KNAT2 which were related to the development of shoot apical meristem. These results from the present research help to reveal the molecular mechanism of BraYAB1-702 gene in the establishment of adaxial-abaxial polarity of the lateral organs in Chinese cabbage.

[Effect of Biochar Addition on the Diversity and Interaction of Rhizosphere Fungi in Manure-fertilized Soil].

To study the effect of biochar addition on the community structure and interaction of rhizosphere fungi in manure-fertilized soil, a pot experiment with ryegrass (Lolium perenne L.) was performed to assess community succession and the molecular ecological network of rhizosphere fungi with the addition of 2% (w/w) biochar and manure-only treatments. The results of Illumina MiSeq sequencing indicated that there was no significant difference between the soil fungal α-diversity (Shannon index) of the control group and that of the biochar group. Ascomycota, Basidiomycota, and Zygomycota were the dominant fungal phyla across all samples with relative abundances ranging from 59.64% to 84.80%, 1.90% to 5.87%, and 4.34% to 16.11%, respectively. Molecular ecological network analysis indicated that fungal communities in the biochar treatment had more complex associations and significantly enhanced positive correlations compared to those of the control group (P<0.05). Mantel test analysis indicated that plant root was significantly correlated with fungal abundance and community interactions in the biochar treatment (P=0.001). Plant root was the most important factor in altering fungal abundance and interactions.

iTRAQ-based proteomics screen for potential regulators of wheat (Triticum aestivum L.) root cell wall component response to Al stress.

OBJECTIVE: The inhibition of Aluminum (Al)-induced root tip cell elongation is a major cause of plant root elongation suppression. The inhibition of root tip cell elongation is caused by a disruption of cell wall component metabolism, growth signaling, or cellular damage. The aim of this study was to identify the proteins involved in the metabolism of the root cell wall components under Al stress in the Al-tolerant wheat (Triticum aestivum L.) cultivar ET8. METHODS: Differentially expressed proteins of Al-tolerant wheat roots were screened via isobaric tags for relative and absolute quantification (iTRAQ). Furthermore, their expression changes were detected via RT-PCR analysis. The contents of major components of the cell wall and their changes in metabolic enzyme activities were also investigated. RESULTS: A total of 97 differentially expressed proteins from Al-tolerant wheat roots were screened and nine of these 97 proteins were root cell wall component related. The known nucleic acid sequences of proteins were 14-3-3 protein, the plasm membrane (PM) H+-ATPase, phospholipase D, peroxidase, and glycosyltransferase. For 14-3-3 protein, phospholipase D and peroxidase, the protein expression and mRNA expression were consistent with Al-treatment; however, for PM H+-ATPase and glycosyltransferase, the protein expression and mRNA expression were inconsistent under Al-stress. Furthermore, both cellulase activity and callase activity were down-regulated by Al stress, while the phenylalanineammonialyase (PAL), cinnamyl alcohol dehydrogenase (CAD), and peroxidase (POD) activities were up-regulated. Furthermore, the PM H+-ATPase activity was decreased in response to Al stress. In addition, the contents of callose, cellulose, lignin, and H2O2 varied significantly. CONCLUSIONS: The cell wall components, relative metabolism enzymes activity, and gene expression also changed followed by protein expression changed in response to Al stress. The results suggest that Al stress leads to marked variations in metabolic enzyme activity, carbohydrate content, followed by changes of root cell components in wheat roots.