Arabidopsis DREB2A is a key transcription factor of heat- and drought-responsive gene expression, and DREB2A expression is induced by these stresses. We analyzed the DREB2A promoter and found a heat shock element that functions as a cis-acting element in the heat shock (HS)-responsive expression of DREB2A. Among the 21 Arabidopsis heat shock factors, we chose 4 HsfA1-type proteins as candidate transcriptional activators (HsfA1a, HsfA1b, HsfA1d, and HsfA1e) based on transactivation activity and expression patterns. We generated multiple mutants and found that the HS-responsive expression of DREB2A disappeared in hsfa1a/b/d triple and hsfa1a/b/d/e quadruple mutants. Moreover, HS-responsive gene expression, including that of molecular chaperones and transcription factors, was globally and drastically impaired in the hsfa1a/b/d triple mutant, which exhibited greatly reduced tolerance to HS stress. HsfA1 protein accumulation in the nucleus was negatively regulated by their interactions with HSP90, and other factors potentially strongly activate the HsfA1 proteins under HS stress. The hsfa1a/b/d/e quadruple mutant showed severe growth retardation, and many genes were downregulated in this mutant even under non-stress conditions. Our study indicates that HsfA1a, HsfA1b, and HsfA1d function as main positive regulators in HS-responsive gene expression and four HsfA1-type proteins are important in gene expression for normal plant growth.

This study creates a compendium of gene expression in normal human tissues suitable as a reference for defining basic organ systems biology. Using oligonucleotide microarrays, we analyze 59 samples representing 19 distinct tissue types. Of ∼7,000 genes analyzed, 451 genes are expressed in all tissue types and designated as housekeeping genes. These genes display significant variation in expression levels among tissues and are sufficient for discerning tissue-specific expression signatures, indicative of fundamental differences in biochemical processes. In addition, subsets of tissue-selective genes are identified that define key biological processes characterizing each organ. This compendium highlights similarities and differences among organ systems and different individuals and also provides a publicly available resource (Human Gene Expression Index, the HuGE Index, http://www.hugeindex.org ) for future studies of pathophysiology.

DREB2s (dehydration-responsive element-binding protein 2s) are transcription factors that interact with a cis-acting DRE (dehydration-responsive element)/CRT (C-repeat) sequence and activate the expression of downstream genes involved in water- and heat-shock stress responses and tolerance in Arabidopsis thaliana. In this study, we performed a comprehensive analysis of all five DREB2-type genes in rice (OsDREB2 s: OsDREB2A, OsDREB2B, OsDREB2C, OsDREB2E and OsABI4) to determine which of them contribute to plant stress responses. We analysed the expression patterns of these genes under abiotic stress conditions, and we examined the subcellular localisation and transcriptional activation activity of their translational products in protoplasts. Only OsDREB2A and OsDREB2B showed abiotic stress-inducible gene expression. In addition, OsDREB2B showed nuclear specific localisation and the highest transactivation activity. OsDREB2B has functional and non-functional forms of its transcript similar to its orthologues in the grass family, and the functional form of its transcript was markedly increased during stress conditions. We analysed the splicing mechanism of OsDREB2B with transgenic rice that express the non-functional transcript and we found that the non-functional form is not a precursor of the functional form; thus, stress-inducible alternative splicing of pre-mRNA is an important mechanism for the regulation of OsDREB2B. Transgenic Arabidopsis plants overexpressing OsDREB2B showed enhanced expression of DREB2A target genes and improved drought and heat-shock stress tolerance. These results suggest that OsDREB2B is a key gene that encodes a stress-inducible DREB2-type transcription factor that functions in stress-responsive gene expression in rice.

Running title: SALT STRESS FOR ACCUMULATION OF LIPIDSIn order to get the high liquefaction yield from marine algae cell mass to fuel oil, the effect of salt stress on the accumulation of lipids and triacylglyceride in Dunaliella cells was investigated. Although initial NaCl concentration higher than 1.5 M markedly inhibited cell growth, increase of initial NaCl concentration from 0.5 (equal to sea water) to 1.0 M resulted in a higher intracellular lipid content (67%) in comparison with 60% for the salt concentration of 0.5 M. Addition of 0.5 or 1.0 M NaCl at mid-log phase or the end of log phase during cultivation with initial NaCl concentration of 1.0 M further increased the lipid content (70%). Since atmospheric CO 2 accumulation has a serious effect on the global environment, the control of total CO 2 emission into the atmosphere is considered to be an important issue related to the biosphere. Marine microalgae are expected to play an important role in resolving this problem because they have a high capability for photosynthesis and grow well in the sea which solubilizes a high amount of CO 2 and which accounts for 70% of the surface area of the earth. There are two major approaches to large-scale CO 2 fixation by marine microalgae.One is the production of non-carbon energy sources such as hydrogen gas from the algal biomass. The other is the conversion of algal biomass into liquid fuel oil by thermochemical liquefaction reactions at a high temperature and pressure (1). The latter process is expected to stimulate CO 2 circulation on earth, and is considered to be a simpler and more appropriate process for worldwide implementation than the former.One of the most important criteria in assessing the performance of thermochemical liquefaction is the oil yield from the organic materials in the algal biomass. A report on liquefaction using various model substrates revealed that a high liquefaction yield was obtained from cell components containing hydrophobic compounds such as lipids, fatty acids and fatty acid esters (2). Among marine microalgae species, cells of the genus Nannochloris are known to contain a large amount of intracellular lipids (3, 4). It was reported that the intracellular triacylglyceride content increased after nitrate depletion during a cultivation of Nannochloris sp. UTEX LB1999 cells 2 3 in modified NORO medium containing 9.9 mM KNO 3 even though the intracellular lipid content did not increase and the oil yield following liquefaction of the cells increased in proportion to the intracellular triacylglyceride content (5). When 0.9 mM nitrate was intermittently fed 10 times during the log phase in addition to initial nitrate feed (0.9 mM), the concentration of Nannochloris sp. UTEX LB1999 reached almost the same (2.16 g/l) and the contents of intracellular lipids and the percentage of triacylglycerides in the lipids were respectively increased from 31.0% to 50.9% and 26.0% to 47.6%, compared with those of cells cultured in a modified NORO medium containing 9.9 mM KNO 3 without additional nitra...

Mononegavirus gene expression is generally monocis-2 Corresponding author tronic, each mRNA usually directing a single primary translation product. However, the P gene of the subfamily The Sendai virus (SeV) V protein is characterized by Paramyxovirinae in the Paramyxoviridae is a notable the unique cysteine-rich domain in its carboxy-terminal exception, because it gives rise to multiple protein species half which is fused to the amino-terminal half of the by means of overlapping frames and by a remarkable P protein, but its function has remained enigmatic.process known as RNA editing or pseudotemplated addiThe V protein-directing mRNA is generated by a tion of nucleotides (for review, see Lamb and Kolakofsky, remarkable process known as mRNA editing involving 1996). The P gene is the second proximal to the 3Ј-terminus the pseudotemplated addition of a single G residue at in these viruses. RNA editing to insert pseudotemplated G a specific septinucleotide locus in the P gene, whereas residues is found for all the three paramyxovirus genera. the unedited exact copy encodes the P protein. Here, It is a virus-specific event which takes place co-transcripwe introduced two nucleotide changes in the septitionally by reiterative copying of the short C stretch at a nucleotide motif (UUUUCCC to UUCUUCC) in a fullspecific region on the genome template (Vidal et al., length SeV cDNA and were able to recover a virus 1990a). The septinucleotide consensus motif (3Ј-UUU/ from the cDNA, which was devoid of mRNA editing CUCCC-5Ј) including the C stretch has been proposed to and hence unable to synthesize the V protein. Combe a requirement for editing (Park and Krystal, 1992). A pared with the parental wild-type virus with regard to 'stuttering' model proposes that the polymerase pauses at gene expression, replication and cytopathogenicity in this site and, when the pause is sufficiently long, slippage various cell lines in vitro, the V(-) virus was found of the nascent mRNA occurs by one or two nucleotides, to be either potentiated or comparable but never thereby reiteratively inserting one or two Gs (Thomas attenuated. The V(-) virus, however, showed markedly et al., 1988;Vidal et al., 1990b). For Sendai virus (SeV) attenuated in vivo replication capacity in and patho- (Figure 1), bovine parainfluenza virus type 3 (genus genicity for mice. Thus, though categorized as a nonParamyxovirus) and measles virus (Morbillivirus), the essential gene product, SeV V protein encodes a luxury unedited mRNA that is the exact copy of the P gene function required for in vivo pathogenicity.encodes the P (phospho) protein, while the addition of Keywords: mRNA editing/pathogenicity/reverse genetics/ one G residue produces an mRNA that encodes the V Sendai virus/V(-) mutant protein (Vidal et al., 1990a;Galinski et al., 1992). The edited version (with insertion of one or two G residues) encodes the P protein and the unedited version the V protein for the genus Rubulavirus including SV5 (Thomas