PubMed Health⌕ Search

Biomedical subjects

Seiji Tateyama

Publications and source records attributed to Seiji Tateyama.

6 recordsLinked to original sources

Affinity selection of DNA-binding protein complexes using mRNA display.

Comprehensive analysis of DNA-protein interactions is important for mapping transcriptional regulatory networks on a genome-wide level. Here we present a new application of mRNA display for in vitro selection of DNA-binding protein heterodimeric complexes. Under improved selection conditions using a TPA-responsive element (TRE) as a bait DNA, known interactors c-fos and c-jun were simultaneously enriched about 100-fold from a model library (a 1:1:20 000 mixture of c-fos, c-jun and gst genes) after one round of selection. Furthermore, almost all kinds of the AP-1 family genes including c-jun, c-fos, junD, junB, atf2 and b-atf were successfully selected from an mRNA display library constructed from a mouse brain poly A(+) RNA after six rounds of selection. These results indicate that the mRNA display selection system can identify a variety of DNA-binding protein complexes in a single experiment. Since almost all transcription factors form heterooligomeric complexes to bind with their target DNA, this method should be most useful to search for DNA-binding transcription factor complexes.

Animals↗

Cell-free cotranslation and selection using in vitro virus for high-throughput analysis of protein-protein interactions and complexes.

We have developed a simple and totally in vitro selection procedure based on cell-free cotranslation using a highly stable and efficient in vitro virus (IVV). Cell-free cotranslation of tagged bait and prey proteins is advantageous for the formation of protein complexes and allows high-throughput analysis of protein-protein interactions (PPI) as a result of providing in vitro instead of in vivo preparation of bait proteins. The use of plural selection rounds and a two-step purification of the IVV selection, followed by in vitro post-selection, is advantageous for decreasing false positives. In a single experiment using bait Fos, more than 10 interactors, including not only direct, but also indirect interactions, were enriched. Further, previously unidentified proteins containing novel leucine zipper (L-ZIP) motifs with minimal binding sites identified by sequence alignment as functional elements were detected as a result of using a randomly primed cDNA library. Thus, we consider that this simple IVV selection system based on cell-free cotranslation could be applicable to high-throughput and comprehensive analysis of PPI and complexes in large-scale settings involving parallel bait proteins.

Animals↗

Dolichols of the fern Matteucia struthiopteris.

Dolichols isolated from leaves of the fern Matteucia struthiopteris were present as a mixture of prenologues composed of 14 up to 20 isoprene units with Dol-16 dominating. They comprised approximately 0.004% of the fresh weight of fresh plant tissue and were accompanied by traces of polyprenols (Pren-14 up to Pren-17, Pren-16 dominating). Their structure was confirmed by electropray ionization mass spectrometry (ESI-MS). This is the first time that dolichols have been reported as dominating polyisoprenoid alcohols in plant photosynthetic tissue.

Chromatography, High Pressure Liquid↗

In vitro selection of Jun-associated proteins using mRNA display.

Although yeast two-hybrid assay and biochemical methods combined with mass spectrometry have been successfully employed for the analyses of protein-protein interactions in the field of proteomics, these methods encounter various difficulties arising from the usage of living cells, including inability to analyze toxic proteins and restriction of testable interaction conditions. Totally in vitro display technologies such as ribosome display and mRNA display are expected to circumvent these difficulties. In this study, we applied an mRNA display technique to screening for interactions of a basic leucine zipper domain of Jun protein in a mouse brain cDNA library. By performing iterative affinity selection and sequence analyses, we selected 16 novel Jun-associated protein candidates in addition to four known interactors. By means of real-time PCR and pull-down assay, 10 of the 16 newly discovered candidates were confirmed to be direct interactors with Jun in vitro. Furthermore, interaction of 6 of the 10 proteins with Jun was observed in cultured cells by means of co-immunoprecipitation and observation of subcellular localization. These results demonstrate that this in vitro display technology is effective for the discovery of novel protein-protein interactions and can contribute to the comprehensive mapping of protein-protein interactions.

Animals↗

Polyisoprenoid alcohols from the mushroom Lentinus edodes.

Lipids extracted from the shiitake mushroom Lentinus edodes contain dolichols composed of 15 up to 19 isoprene units with Dol-17 as the dominating prenologue. Identification of dolichols was achieved by the application of 2D-TLC, HPLC and electrospray ionization mass spectrometry. Additionally a family of polyprenols (alpha-unsaturated counterparts) with the same chain-length was also detected. Dolichols comprised approximately 0.002% of the fresh weight of the mushroom. Dolichols accompanied by traces of polyprenols are for the first time found in the mushroom tissue.

Alcohols↗

Highly stable and efficient mRNA templates for mRNA-protein fusions and C-terminally labeled proteins.

For high-throughput in vitro protein selection using genotype (mRNA)-phenotype (protein) fusion formation and C-terminal protein labeling as a post-selection analysis, it is important to improve the stability and efficiency of mRNA templates for both technologies. Here we describe an efficient single-strand ligation (90% of the input mRNAs) using a fluorescein-conjugated polyethylene glycol puromycin (Fluor-PEG Puro) spacer. This ligation provides a stable c-jun mRNA with a flexible Fluor-PEG Puro spacer for efficient fusion formation (70% of the input mRNA with the PEG spacer) in a cell-free wheat germ translation system. When using a 5' untranslated region including SP6 promoter and Omega29 enhancer (a part of tobacco mosaic virus Omega), an A(8) sequence (eight consecutive adenylate residues) at the 3' end is suitable for fusion formation, while an XA(8) sequence (XhoI and the A(8) sequence) is suitable for C-terminal protein labeling. Further, we report that Fluor-PEG N-t-butyloxycarbonylpuromycin [Puro(Boc)] spacer enhances the stability and efficiency of c-jun mRNA template for C-terminal protein labeling. These mRNA templates should be useful for puromycin-based technologies (fusion formation and C-terminal protein labeling) to facilitate high-throughput in vitro protein selection for not only evolutionary protein engineering, but also proteome exploration.

3' Untranslated Regions↗