Neuropeptides regulate a wide range of animal behavior including food consumption, circadian rhythms, and anxiety. Recently, Drosophila neuropeptide F, which is the homolog of the vertebrate neuropeptide Y, was cloned, and the function of Drosophila neuropeptide F in feeding behaviors was well characterized. However, the function of the structurally related short neuropeptide F (sNPF) was unknown. Here, we report the cloning, RNA, and peptide localizations, and functional characterizations of the Drosophila sNPF gene. The sNPF gene encodes the preprotein containing putative RLRF amide peptides and was expressed in the nervous system of late stage embryos and larvae. The embryonic and larval localization of the sNPF peptide in the nervous systems revealed the larval central nervous system neural circuit from the neurons in the brain to thoracic axons and to connective axons in the ventral ganglion. In the adult brain, the sNPF peptide was localized in the medulla and the mushroom body. However, the sNPF peptide was not detected in the gut. The sNPF mRNA and the peptide were expressed during all developmental stages from embryo to adult. From the feeding assay, the gainof-function sNPF mutants expressed in nervous systems promoted food intake, whereas the loss-of-function mutants suppressed food intake. Also, sNPF overexpression in nervous systems produced bigger and heavier flies. These findings indicate that the sNPF is expressed in the nervous systems to control food intake and regulate body size in Drosophila melanogaster.Neuropeptides regulate a wide range of animal behavior. In vertebrates, neuropeptide Y (NPY) 1 regulates food consumption, circadian rhythms, anxiety, and other physiological processes (1). NPY, a 36-amino acid neuromodulator, is expressed abundantly in the mammalian brain and controls feeding (2). The NPY injection into the hypothalamus of rat brain resulted in hyperphagia and obesity, whereas the NPY-deficient mouse in the leptin mutant background (NPYϪ/Ϫ; ob/ob) showed the less obese phenotype (3).In invertebrates, neuropeptide F (NPF) peptides share structural similarity with the vertebrate NPY (4). NPF peptides isolated from various invertebrate animals have the conserved (A/L)R(P/L)RF amide sequence at their C-terminal ends (5, 6). From a completely sequenced Drosophila melanogaster genome, short NPF (sNPF; CG13968) and Drosophila NPF (dNPF; CG10342) were found. The dNPF peptide was isolated by the radioimmunoassay. The preprotein is processed to the 36-amino acid peptide containing RVRF amide in the C terminus. dNPF is considered the homolog of the vertebrate NPY. dNPF mRNA and peptide are expressed in the brain and midgut of Drosophila larvae and adults (7). The dNPF neural network in the larval central nervous system (CNS) is changed by the gustatory stimulation of sugar, indicating that dNPF is an integral part of the chemosensory system that regulates eating behavior (8). Drosophila larvae eat continuously and grow in a relatively short period. About 5 days after egg laying, they s...

The proto-oncogene protein DEK has been implicated in the t(6;9) chromosomal translocation associated with a subtype of acute myelogenous leukemia (AML), which results in the formation of a DEK-CAN fusion protein. Histone acetylation is an important post-translational modification which is involved in transcriptional regulation. In this study, we report that the acidic domain containing protein DEK interacts with histones and exerts a potent inhibitory effect on both p300 and PCAF-mediated histone acetyltransferase activity and transcription. Using chromatin immunoprecipitation assays, we have demonstrated that the recruitment of DEK to the appropriate promoter induces the histone H3 and H4 hypoacetylation of chromatin. Collectively, our data illustrate the important regulatory role played by protein DEK in transcriptional regulation, and suggest that transcription-regulating acidic domain regions may play a role in leukemogenesis.

As a nuclear phosphoprotein, proto-oncogene protein DEK is capable to changing chromatin structure. DEK was recently identified as an inhibitor of histone acetylation mediated by p300 and PCAF and to facilitate transcriptional repression. To elucidate the biological functions of DEK in vivo, we have constructed transgenic flies that overexpress the human DEK in the developing eye. Transgenic flies developed a severe rough eye phenotype, which is indicative of ectopically induced apoptosis. Genetic and biochemical analyses, including the rescue of the apoptotic phenotype by pan-caspase inhibitor protein p35 and caspase activity analyses, suggested that DEK induces apoptotic cell death through a caspases-9 and -3 dependent pathway. Using extracts from larval salivary glands, we have determined that the global histone acetylation levels of histone H3 Lys9 and H4 Lys5 were decreased upon DEK overexpression. Using chromatin immunoprecipitation assays, we have demonstrated that overexpression of DEK induced the histone H3 and H4 hypoacetylation of promoter of the antiapoptotic gene bcl-2. Co-expression of bcl-2 also rescued apoptosis and the reduced expression of bcl-2 gene was analyzed by real-time PCR. Our results indicate that acidic domain containing protein DEK might have a role in modulating both transcriptional regulation and apoptosis through HAT inhibitory activity.

Metabolism of brassinolide in Marchantia polymorpha was investigated by use of in vivo suspension cultured cells. GC-MS analysis of metabolites derived from non-labelled brassinolide and [26, 28-2H6] brassinolide revealed that brassinolide was converted to 26-norbrassinolide while [26, 28-2H6]brassinolide to [26-2H3]28-norbrassinolide. It seems that Marchantia cells recognized [26, 28-2H6]brassinolide as a xenobiotic rather than brassinolide and deteriums attached to C-28 significantly affect demethylation reaction due to isotopic effect. Thus, demethylation of brassinolide in planta seems to proceed by loss of C-26 rather than C-28. The present finding is the first evidence for demethylation metabolism of brassinosteroids. The biological activity of 26-norbrassinolide was 10-fold reduced as shown by the rice lamina inclination test. However, because of its high biological activity, it remains difficult to conclude whether or not C-26 demethylation serves as an important deactivation process of brassinolide.