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Influenza virus PB1 protein plays the key role for the assembly and catalytic function of viral RNA polymerase. We showed that Ebp1 interacted with PB1 and interfered both the viral RNA polymerase function in vitro and the virus growth. The Ebp1 expression was induced by influenza virus infection using western blotting and quantitative real time PCR assay. However, the quantitative determination has been requested of the relationship between influenza virus growth and Ebp1 level. To analyze the relationship between virus growth and Ebp1 level, we developed the assay system of single cell. Using this system, we confirmed the tight correlation between the Ebp1 level and the influenza virus growth.

Influenza virus attaches on the sialic acid on cellular membrane through it's HA protein and enters cytoplasm by receptor-mediated endocytosis, then move from endocytic vesicles to early endosomes and late endosome where the influenza viruses fuse with the endosomal membrane to release viral genome followed to transport the genome to nuclei where virus replicate their genome. Previously we found that host cell protein Ebpl (ErbB3 binding protein 1) interacted with the catalytic subunit PB1 of influenza virus RNA dependent RNA polymerase and interfered with its function. Ebpl expression is regulated by cell cycle, showing high level expression especially in Gl to S phase. Recently we identified another host protein (PA4c9) interacts with subunit PA of influenza virus RNA polymerase. Again PA4c9 is one of the cell cycle dependent proteins. These findings encouraged us to investigate the host cell cycle dependency of influenza infection. To identify the cell phase at which influenza virus attach most efficiently, the cells were treated with the fluorescent-labeled influenza viruses for 5-15 minutes and fixed with paraformaldehyde followed by observation under the confocal microscope. In parallel, attempts were made to manipulate a single particle of fluorescent-labeled virus using laser manipulator for infection onto a single cell at different phase. The results altogether indicated that influenza virus preferred the membrane of stable cell phase (G0/G1) to attach for infection.

We propose in situ formation of gel microbeads made of a thermoreversible hydrogel for indirect laser micromanipulation of microorganisms, DNA and viruses. Irradiation, using a 1064 nm laser, of an aqueous solution mixed with poly-(N-isopropylacrylamide) through a high magnification lens resulted in the formation of a gel microbead at the laser focus due to heating. The gel microbead was trapped by the laser, and was used for indirect laser micromanipulation of microscale and nanoscale samples. Laser tweezers can typically handle a microscale object with size ranging from several tens of nm to several hundreds of ?m in a stable manner. However, a nanoscale object with a size of a few nm cannot be stably manipulated, and laser beam heating is a major problem. This paper shows a method of indirect manipulation of microorganisms, DNA and viruses using a gel microbead made from the poly-(N-isopropylacrylamide) aqueous solution. We succeeded in reducing the laser power for gel microbead formation, and in using the laser-trapped gel microbead for the manipulation of microorganisms, DNA and viruses.

A novel UWB short-range radar (SRR) which effectively mitigates its impacts on radio services using the restricted band such as radio astronomy or Earth Exploring Satellite Service is introduced. The essential components, a burst oscillator generating no carrier leak, and antennas with notch-filtering function are presented in detail. Other key MMICs, such as a high-speed square-law detector, variable gain LNA, a sample-hold circuit, etc. are also described with the performances of the SRR.

Influenza virus RNA polymerase is composed of three subunits, PB1, PB2 and PA, which is involved in both transcription and replication of viral genome RNA, negative strand RNA. Influenza virus gene product RNA dependent RNA polymerase synthesizes two different RNAs, one is mRNA and another is cRNA which become a template for virus genome RNA synthesis. To synthesize two different RNAs the RNA polymerase should be converted by some factor(s) in the virus infected cell. It was speculated that between polymerase structure and function could be some relations. It is started to screen the protein(s) which interact(s) with RNA polymerase using yeast two-hybrid screening system. Nine host proteins were identified, which interacted with different polymerase subunits. One of them, PB1c45, which interacted with PB1 subunit in polymerase and molecular weight was 45kDa, was analyzed the effect on polymerase activity and influenza virus infectivity. The PB1c45 inhibited the polymerase activity and also reduced the influenza virus infectivity.