Hirohide Saito

Synthetic messenger RNA (mRNA) tools often use pseudouridine and 5-methyl cytidine as substitutions for uridine and cytidine to avoid the immune response and cytotoxicity induced by introducing mRNA into cells. However, the influence of base modifications on the functionality of the RNA tools is poorly understood. Here we show that synthetic mRNA switches containing N1-methylpseudouridine (m1Ψ) as a substitution of uridine substantially out-performed all other modified bases studied, exhibiting

The CRISPR-Cas9 system is a powerful genome-editing tool useful in a variety of biotechnology and biomedical applications. Here we developed a synthetic RNA-based, microRNA (miRNA)-responsive CRISPR-Cas9 system (miR-Cas9 switch) in which the genome editing activity of Cas9 can be modulated through endogenous miRNA signatures in mammalian cells. We created miR-Cas9 switches by using a miRNA-complementary sequence in the 5΄-UTR of mRNA encoding Streptococcus pyogenes Cas9. The miR-21-Cas9 or miR-3

Individual expression: We describe a method that allows the observation of real-time gene expression in a large number of individual giant liposomes encapsulating identical genetic material. We followed the gene expression profiles from DNA and mRNA templates coding for different proteins. Although the average profiles of individual liposomes were similar to those measured in bulk solution, strong variability between individual liposomes was observed at both transcription and translation.

Understanding how to control cell fate is crucial in biology, medical science and engineering. In this study, we introduce a method that uses an intracellular protein as a trigger for regulating human cell fate. The ON/OFF translational switches, composed of an intracellular protein L7Ae and its binding RNA motif, regulate the expression of a desired target protein and control two distinct apoptosis pathways in target human cells. Combined use of the switches demonstrates that a specific protein

Synthetic messenger RNA (mRNA) has been focused on as an emerging application for mRNA-based therapies and vaccinations. Recently, synthetic circular RNAs (circRNAs) have shown promise as a new class of synthetic mRNA that enables superior stability and persistent gene expression in cells. However, translational control of circRNA remained challenging. Here, we develop 'circRNA switches' capable of controlling protein expression from circRNA by sensing intracellular RNA or proteins. We designed

Synthetic biology has great potential for future therapeutic applications including autonomous cell programming through the detection of protein signals and the production of desired outputs. Synthetic RNA devices are promising for this purpose. However, the number of available devices is limited due to the difficulty in the detection of endogenous proteins within a cell. Here, we show a strategy to construct synthetic mRNA devices that detect endogenous proteins in living cells, control transla

Human induced pluripotent stem cells (iPSCs) are promising cell resources for cell therapy and drug discovery. However, iPSC-derived differentiated cells are often heterogenous and need purification using a flow cytometer, which has high cost and time consumption for large-scale purification. MicroRNAs (miRNAs) can be used as cell selection markers, because their activity differs between cell types. Here, we show miRNA-responsive ON and OFF switch mRNAs for robust cell purification. The ON switc

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Ribozyme Exclusively Aminoacylates the 3'-Hydroxyl Group of the tRNA Terminal AdenosineHirohide Saito and Hiroaki SugaView Author Information Department of Chemistry, University at Buffalo State University of New York Buffalo, New York, 14260-3000 Department of Chemistry and Biotechnology Graduate School of Engineering, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan Cite this: J. Am. Chem. Soc. 2001, 123, 29, 7178–7179Public

Anti-CRISPR proteins have the potential to regulate CRISPR-Cas systems in a cell-type-specific manner. To selectively edit the genome in target cells, we controlled the expression of AcrllA4, a <i>Streptococcus pyogenes</i> Cas9 inhibitor, based on endogenous microRNA (miRNA) activity. We designed a miRNA-responsive AcrllA4 switch, which is a synthetic mRNA that contains a completely complementary sequence to an arbitrary miRNA at the 5'-UTR region and encodes <i>AcrllA4</i>. Together with the C