Proteins that specifically bind double-stranded RNA (dsRNA) are involved in the regulation of cellular signaling events and gene expression, and are characterized by a conserved dsRNA-binding motif (dsRBM). Here we report the biochemical properties of nine such gene products, each containing one or two dsRBMs: four Arabidopsis Dicer-like proteins (DCL1-4), Arabidopsis HYL1 and four of its homologs (DRB2, DRB4, DRB5 and OsDRB1). DCL1, DCL3, HYL1 and the four HYL1 homologs exhibit significant dsRNA-binding activity, indicating that these proteins are involved in RNA metabolism. The dsRBMs from dsRBM-containing proteins (dsRBPs) also function as a protein-protein interaction domain and homo- and heterodimerization are essential for biological functioning of these proteins. We show that DRB4 interacts specifically with DCL4, and HYL1 most strongly interacts with DCL1. These results indicate that each HYL1/DRB family protein interacts with one specific partner among the four Dicer-like proteins. Localization studies using GFP fusion proteins demonstrate that DCL1, DCL4, HYL1 and DRB4 localize in the nucleus, while DRB2 is present in the cytoplasm. Subcellular localizations of HYL1, DRB4, DCL1 and DCL4 further strengthen the notion that HYL1 and DCL1, and DRB4 and DCL4, exist as complexes. The presented data suggest that each member of the HYL1/DRB protein family may individually modulate Dicer function through heterodimerization with a Dicer-like protein in vivo.

Transcription and mRNA processing are regulated by phosphorylation and dephosphorylation of the C-terminal domain (CTD) of RNA polymerase II, which consists of tandem repeats of a Y 1 S 2 P 3 T 4 S 5 P 6 S 7 heptapeptide. Previous studies showed that members of the plant CTD phosphatase-like (CPL) protein family differentially regulate osmotic stress-responsive and abscisic acidresponsive transcription in Arabidopsis thaliana. Here we report that AtCPL1 and AtCPL2 specifically dephosphorylate Ser-5 of the CTD heptad in Arabidopsis RNA polymerase II, but not Ser-2. An N-terminal catalytic domain of CPL1, which suffices for CTD Ser-5 phosphatase activity in vitro, includes a signature DXDXT acylphosphatase motif, but lacks a breast cancer 1 CTD, which is an essential component of the fungal and metazoan Fcp1 CTD phosphatase enzymes. The CTD of CPL1, which contains two putative doublestranded RNA binding motifs, is essential for the in vivo function of CPL1 and includes a C-terminal 23-aa signal responsible for its nuclear targeting. CPL2 has a similar domain structure but contains only one double-stranded RNA binding motif. Combining mutant alleles of CPL1 and CPL2 causes synthetic lethality of the male but not the female gametes. These results indicate that CPL1 and CPL2 exemplify a unique family of CTD Ser-5-specific phosphatases with an essential role in plant growth and development.T ranscriptional induction of genes that encode stress tolerance determinants is an integral part of the survival strategy of plants in adverse environments. The Arabidopsis thaliana responsive to dehydration (RD) genes are prototypal outputs of stress signal integration activated by low temperature, hyperosmolarity, and the plant hormone abscisic acid (ABA). The stress-inducible promoter of the RD29a gene contains dehydration͞cold-responsive elements and ABA-responsive elements that are the targets of distinct families of DNA binding transcription factors (1, 2). The plant stress response is also regulated by proteins that impact the core RNA polymerase II (Pol II) transcriptional machinery, the mRNA maturation process, and chromatin structure (3-9). Analysis of Arabidopsis mutants that display hyperinduction of RD29a expression under stress conditions have identified a family of C-terminal domain (CTD) phosphatase-like (CPL) genes that negatively regulate stressresponsive transcription (5, 6). The CPL1 and CPL3 genes discovered in the screen for hyperinduction are so named because they encode large polypeptides (967 and 1,241 aa, respectively) with local primary structure similarity to the Fcp1 family of fungal and metazoan protein serine phosphatases, which regulate transcription by dephosphorylating the CTD of the largest subunit of RNA Pol II (10).The Pol II CTD is composed of a tandemly repeated heptapeptide of consensus sequence Y . The number of CTD heptad repeats varies widely among species and correlates roughly with evolutionary complexity; e.g., mammals have 52 repeats, Drosophila has 42 repeats, fission yeast Schizosacc...

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The performance of a composite film of polypyrrole (PPy) and poly(4-styrenesulfonate) (PSS) was studied in combination with an organic electrolyte as a possible lithium battery cathode. The composite film had a fairly flat morphology and exhibited electroactivity in organic electrolyte solutions using dimethylsulfoxide and propylene carbonate (PC) solvents. We confirmed that during the redox process the film charge was compensated with cations. A lithium cell consisting of the composite film as a cathode and an LiCIO4-PC electrolyte worked as a rechargeable battery. The energy density of the PPy/PSS cathode was calculated to be 220 Wh liter -I and the average output voltage of the rechargeable cell was 2.9 V.

Interface roughness and local electronic states formed in GaAs quantum wells ͑QWs͒ grown on ͑110͒ cleaved surfaces were characterized by high-resolution microscopic photoluminescence ͑micro-PL͒ imaging and spectroscopy assisted by a solid immersion lens. From macroscopic PL spectra and micro-PL images, it was found that well width fluctuation of about 0.6 to 0.7 nm, which corresponds to 3 to 3.5 monolayers ͑ML͒, with laterally sub-m-to m-scale ML terraces existed in the ͑110͒ GaAs/AlAs QWs, and this was also supported by the results of atomic force microscopy measurements performed on the ͑110͒ GaAs surface. In high-resolution solid-immersion micro-PL spectroscopy, sharp PL peaks were observed at low excitation power and their temperature and excitation power dependence showed a localized quantum-dot-like ͑QD-like͒ nature in the ͑110͒ GaAs QWs. The spatial and spectral distribution of these sharp PL peaks indicated that the localized QD-like states were formed by short-scale roughness in the bottom GaAs-on-AlAs interface of the ͑110͒ GaAs/AlAs QWs on each m-scale large ML terrace in the top AlAs-on-GaAs interface.

Class 1 ribonuclease III (RNase III), found in bacteria and yeast, is involved in processing functional RNA molecules such as ribosomal RNAs (rRNAs). However, in Arabidopsis thaliana, the lack of an obvious phenotype or quantitative change in mature rRNAs in class 1 RNase III (AtRTL2) mutants and overexpressing plants suggests that AtRTL2 is not involved in rRNA maturation. We characterized the in vitro activity of AtRTL2 to consider its in vivo function. AtRTL2 cleaved double-stranded RNA (dsRNA) specifically in vitro, yielding products of approximately 25 nt or longer in length, in contrast to 10-20 nt long products in bacteria and yeasts. Although dsRNA-binding activity was not detected, the dsRNA-binding domains in AtRTL2 were essential for its dsRNA-cleaving activity. Accumulation of small RNAs derived from transgene dsRNAs was increased when AtRTL2 was transiently expressed in Nicotiana benthamiana leaves by agroinfiltration. These results raise the possibility that AtRTL2 has functions distinct from those of other class 1 RNase IIIs in vivo.

Summary Effects of azuki bean juice supplementation, prescribed according to a Kanpo medicine regimen, on serum lipid concentrations were studied. Healthy young Japanese women were recruited and were randomly assigned to one of the three groups using a parallelgroup design. Control (n = 10), azuki (n = 11) and Concentrated azuki (CA) (n = 12) juice groups consumed 150 g daily of the isocaloric assigned juice for one menstrual cycle with their usual diet. Triglyceride concentrations were decreased in the azuki juice group (p<0.05) and tended to be decreased in the CA juice group (p = 0.055). Triglyceride concentrations in the azuki and CA juice groups decreased by 0.170 mmol/liter (15.4%) and 0.159 mmol/liter (17.9%), respectively (p<0.05). The azuki and CA juice used in this study inhibited pancreatic lipase activity 29.2% and 56.9%, respectively, in vitro. Lipid peroxide changes, based on ANCOVA with the initial level and α-tocopherol changes as covariates, did not differ among the three groups. Serum low density lipoprotein-cholesterol and high density lipoproteincholesterol (HDL) cholesterol concentrations did not change. Thus, azuki bean juice intake, as a traditional Kampo prescription, might be beneficial for preventing hypertriglyceridemia.

Single-cell analysis has become one of the main cornerstones of biotechnology, inspiring the advent of various microfluidic compartments for cell cultivation such as microwells, microtrappers, microcapillaries, and droplets. A fundamental...