Insulin/insulin-like peptide-binding protein (IBP) is abundantly found in venom of the solitary hunting wasp, Eumenes pomiformis (Hymenoptera: Eumenidae). E. pomiformis IBP (EpIBP) is most similar to insect IBP-like proteins that are known to inhibit insect growth and insulin signaling. To investigate the toxicity and target protein, EpIBP was in vivo expressed by Escherichia coli. Spodoptera exigua (Lepidoptera: Noctuidae) larvae injected with EpIBP showed a 20% lower pupation rate than the control larvae, although their body weight was not significantly different from the control when the larvae were provided artificial diet after the injection. EpIBP extended the larval stage without inducing paralysis of S. exigua larvae. To investigate the effects of EpIBP on caterpillar under a starvation condition, survivorship and body weight of the EpIBP-injected were evaluated without providing artificial diet until all the larvae died. The survivorship of the EpIBP-injected larvae was 24-36% higher than the control larvae at 4-5 d post-injection. The body weight of the control larvae reduced to 59% that is approximately 10% lower than the body weight of the EpIBP-injected larvae. These results suggest that EpIBP might inhibit the metabolism of the caterpillars, which is likely related with insulin-like peptide signaling pathway, suppress the loss of body weight and eventually extend the larval stage. An EpIBP-binding protein (EpIBPBP) isolated by immunoprecipitation was matched with a coiled-coil domain-containing protein of the fruit fly. The full-length sequence analysis of EpIBPBP is in progress.

There are increasing interests in developing methods specifically detecting pathogenic Bursaphelenchus xylophilus. In order to develop a detecting method for B .xylophilus, at first we generated monoclonal antibodies (MAbs) specific to B. xylophilus, discriminating from other pine tree resident nematodes. Among 2304 hybridoma fusions screened. We finally selected a MAb clone, 9F10 and used for further study. To identify the antigenic target of MAb-9F10, we employed several biochemical methods such as SDS-PAGE, 2 dimensional electrophoresis, anion exchange chromatography, and immunoprecipitation to separate and isolate an antigenic target. Proteins from above methods were analyzed via nano-LC-ESI-Q-IT-MS. Peptides of GaLECtin were always detected from several proteomic analyses, suggesting that GaLECtin is the antigenic target of MAb-9F10.

Spatial- and temporal-specific expression patterns are primarily regulated at the transcriptional level by the promoter. Therefore, it is important to determine the binding motifs of transcription factors to understand the networks associated with embryogenesis. Here, we used a protein-binding microarray (PBM) to determine the binding motif of OsSMF1, which is a basic leucine zipper transcription factor that is involved in the regulation of rice seed maturation. OsSMF1 (previously called RISBZ1) is known to interact with GCN4 motifs (TGA(G/C)TCA) to regulate seed storage proteins (SSPs). In addition, OsSMF1 (also known as OsbZIP58) functions as a key regulator of starch synthesis in the rice seed. Quadruple 9-mer-based PBM (Q9-PBM) and electrophoretic mobility shift assay (EMSA) experiments revealed that OsSMF1 binds to the ACGT (CCACGT(C/G)), GCN4 (TGA(G/C)TCA), and GCN4-like (GGATGAC) motifs with Kd values of 0.3353 μM, 0.6458 μM, and 1.117 μM, respectively. We also identified 60 putative OsSMF1 target genes using a combination of data from expression microarrays and RiceArrayNet (RAN) analysis. Of these OsSMF1 target genes, 20, 22, and 17 genes contained ACGT, GCN4, and GCN4-like motifs within the 2-kb promoter region, respectively. In addition to known target genes, we also identified 35 potential OsSMF1 target genes that have not been previously described in immature seeds. We also confirmed that OsSMF1 directly regulates Os03g0168500 (thioredoxin-related protein), RPBF, NAC6, and two hypothetical proteins (Os12g0621600 and Os11g0582400) in vivo. This study suggests that OsSMF1 functions in a wide range of seed development processes with specific binding affinities for three DNA binding motifs

Early growth response 1 (Egr1) is a zinc-finger transcription factor to direct second-wave gene expression leading to cell growth, differentiation and/or apoptosis. While it is well-known that Egr1 controls transcription of an array of targets in various cell types, downstream target gene(s) whose transcription is regulated by Egr1 in the uterus has not been identified yet. Thus, we have tried to identify a list of potential target genes of Egr1 in the uterus by performing multi-step in silico promoter analyses. Analyses of mRNA microarray data provided a cohort of genes (102 genes) which were differentially expressed (DEGs) in the uterus between Egr1(+/+) and Egr1(–/–) mice. In mice, the frequency of putative EGR1 binding sites (EBS) in the promoter of DEGs is significantly higher than that of randomly selected non-DEGs, although it is not correlated with expression levels of DEGs. Furthermore, EBS are considerably enriched within –500 bp of DEG’s promoters. Comparative analyses for EBS of DEGs with the promoters of other species provided power to distinguish DEGs with higher probability as EGR1 direct target genes. Eleven EBS in the promoters of 9 genes among analyzed DEGs are conserved between various species including human. In conclusion, this study provides evidence that analyses of mRNA expression profiles followed by two-step in silico analyses could provide a list of putative Egr1 direct target genes in the uterus where any known direct target genes are yet reported for further functional studies.

Early growth response 1 (Egr1) is an immediate early response gene which is induced by various external stimuli and acts as transcription factor to direct second-wave gene expression leading to cell growth, differentiation and/or apoptosis. It is well known that Egr1 regulates transcription of a cluster of genes in cancers and luteinizing hormone (LH) beta subunit in the pituitary. In addition to function of Egr1 in cancers and pituitary, we recently showed that Egr1 acts as a local master regulator to mediate estrogenic actions in the uterus. However, regulatory mechanism by which Egr1 directs transcription of its downstream target genes in the uterus remains to be yet explored. Thus, we have tried to identify direct target genes of Egr1 in the uterus by analyzing mRNA microarray data sets followed by in silico promoter analyses with chromatin immunoprecipitation (CHIP). mRNA expression profiles of Egr1(－/－) uteri and Egr1(－/－) ovaries were compared to those of wildtype mice to provide a potential list of direct target genes of Egr1 in the uterus. Whereas Egr1 is rapidly and transiently induced in the ovary and the uterus by external stimuli, LH and estrogen, respectively with a similar manner, a list of differentially expressed genes between Egr1(+/+) and Egr1(－/－) mice were barely overlapped between these two datasets. This result suggests that the transcriptional network of Egr1 in the uterus is quite different from that in the ovary. The list of differentially expressed genes in Egr1(－/－) uterus was enriched by RT-PCR. In silico analyses with MatInspector provided evidence that Egr1 binding sites are relatively enriched in －500 bp promoter regions of genes in the list. CHIP assays for Egr1 antibody with uterine tissues 2 h after estrogen treatment reinforced the possibility that genes identified in this study such as Gadd45g and Lbh could be directly regulated by Egr1 in uterine context. Collectively, we show that bioinformatic analyses of expression profiles with in silico analyses could be a useful tool to enrich potential candidates of direct target genes of transcription factors.