Colorectal and hepatocellular carcinomas are some of the leading causes of cancer deaths worldwide, but the mechanisms that underly these malignancies are not fully understood. Here we report the identification of SMYD3, a gene that is over-expressed in the majority of colorectal carcinomas and hepatocellular carcinomas. Introduction of SMYD3 into NIH3T3 cells enhanced cell growth, whereas genetic knockdown with small-interfering RNAs (siRNAs) in cancer cells resulted in significant growth suppression. SMYD3 formed a complex with RNA polymerase II through an interaction with the RNA helicase HELZ and transactivated a set of genes that included oncogenes, homeobox genes and genes associated with cell-cycle regulation. SMYD3 bound to a motif, 5'-CCCTCC-3', present in the promoter region of downstream genes such as Nkx2.8. The SET domain of SMYD3 showed histone H3-lysine 4 (H3-K4)-specific methyltransferase activity, which was enhanced in the presence of the heat-shock protein HSP90A. Our findings suggest that SMYD3 has histone methyltransferase activity and plays an important role in transcriptional regulation as a member of an RNA polymerase complex. Furthermore, activation of SMYD3 may be a key factor in human carcinogenesis.

MYB proteins are a superfamily of transcription factors that play regulatory roles in developmental processes and defense responses in plants. We identified 198 genes in the MYB superfamily from an analysis of the complete Arabidopsis genome sequence, among them, 126 are R2R3-MYB, 5 are R1R2R3-MYB, 64 are MYB-related, and 3 atypical MYB genes. Here we report the expression profiles of 163 genes in the Arabidopsis MYB superfamily whose full-length open reading frames have been isolated. This analysis indicated that the expression for most of the Arabidopsis MYB genes were responsive to one or multiple types of hormone and stress treatments. A phylogenetic comparison of the members of this superfamily in Arabidopsis and rice suggested that the Arabidopsis MYB superfamily underwent a rapid expansion after its divergence from monocots but before its divergence from other dicots. It is likely that the MYB-related family was more ancient than the R2R3-MYB gene family, or had evolved more rapidly. Therefore, the MYB gene superfamily represents an excellent system for investigating the evolution of large and complex gene families in higher plants. Our comprehensive analysis of this largest transcription factor superfamily of Arabidopsis and rice may help elucidate the possible biological roles of the MYB genes in various aspects of flowering plants.

Background-Diminished cardiac vagal activity and higher heart rate predict a high mortality rate of chronic heart failure (CHF) after myocardial infarction. We investigated the effects of chronic electrical stimulation of the vagus nerve on cardiac remodeling and long-term survival in an animal model of CHF after large myocardial infarction. Methods and Results-Two weeks after the ligation of the left coronary artery, surviving rats were randomized to vagaland sham-stimulated groups. Using an implantable miniature radio-controlled electrical stimulator, we stimulated the right vagal nerve of CHF rats for 6 weeks. The intensity of electrical stimulation was adjusted for each rat, so that the heart rate was lowered by 20 to 30 beats per minute.

This article reports the results of a study of the unwillingness to communicate, and anxiety of Chinese learners of English as a foreign language (EFL) in English language classrooms. A 70-item survey of 547 first-year undergraduate non-English majors revealed that (a) Most of the students were willing to participate in interpersonal conversations, but many of them did not like to risk using/speaking English in class; (b) more than one third of the students felt anxious in their English language classrooms, and they feared being negatively evaluated and were apprehensive about public speaking and tests; (c) their unwillingness to communicate and their foreign language anxiety correlated significantly with each other and with their selfrated English proficiency and access to English; and (d) many of the variables of interest were good predictors of the students' unwillingness to communicate and of their foreign language anxiety, which were also powerful predictors for each other.

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Auxin is central to many aspects of plant development; accordingly, plants have evolved several mechanisms to regulate auxin levels, including de novo auxin biosynthesis, degradation, and conjugation to sugars and amino acids. Here, we report the characterization of an Arabidopsis thaliana mutant, IAA carboxyl methyltransferase1-dominant (iamt1-D), which displayed dramatic hyponastic leaf phenotypes caused by increased expression levels of the IAMT1 gene. IAMT1 encodes an indole-3-acetic acid (IAA) carboxyl methyltransferase that converts IAA to methyl-IAA ester (MeIAA) in vitro, suggesting that methylation of IAA plays an important role in regulating plant development and auxin homeostasis. Whereas both exogenous IAA and MeIAA inhibited primary root and hypocotyl elongation, MeIAA was much more potent than IAA in a hypocotyl elongation assay, indicating that IAA activities could be effectively regulated by methylation. IAMT1 was spatially and temporally regulated during the development of both rosette and cauline leaves. Changing expression patterns and/or levels of IAMT1 often led to dramatic leaf curvature phenotypes. In iamt1-D, the decreased expression levels of TCP genes, which are known to regulate leaf curvature, may partially account for the curly leaf phenotype. The identification of IAMT1 and the elucidation of its role in Arabidopsis leaf development have broad implications for auxin-regulated developmental process.

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