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Biomedical subjects

Takamasa Inoue

Publications and source records attributed to Takamasa Inoue.

4 recordsLinked to original sources

Adeno-associated virus site-specific integration is regulated by TRP-185.

Adeno-associated virus (AAV) integrates site specifically into the AAVS1 locus on human chromosome 19. Although recruitment of the AAV nonstructural protein Rep78/68 to the Rep binding site (RBS) on AAVS1 is thought to be an essential step, the mechanism of the site-specific integration, particularly, how the site of integration is determined, remains largely unknown. Here we describe the identification and characterization of a new cellular regulator of AAV site-specific integration. TAR RNA loop binding protein 185 (TRP-185), previously reported to associate with human immunodeficiency virus type 1 TAR RNA, binds to AAVS1 DNA. Our data suggest that TRP-185 suppresses AAV integration at the AAVS1 RBS and enhances AAV integration into a region downstream of the RBS. TRP-185 bound to Rep68 directly, changing the Rep68 DNA binding property and stimulating Rep68 helicase activity. We present a model in which TRP-185 changes the specificity of the AAV integration site from the RBS to a downstream region by acting as a molecular chaperone that promotes Rep68 complex formation competent for 3'-->5' DNA helicase activity.

Binding Sites↗

The VP2/VP3 minor capsid protein of simian virus 40 promotes the in vitro assembly of the major capsid protein VP1 into particles.

The SV40 capsid is composed primarily of 72 pentamers of the VP1 major capsid protein. Although the capsid also contains the minor capsid protein VP2 and its amino-terminally truncated form VP3, their roles in capsid assembly remain unknown. An in vitro assembly system was used to investigate the role of VP2 in the assembly of recombinant VP1 pentamers. Under physiological salt and pH conditions, VP1 alone remained dissociated, and at pH 5.0, it assembled into tubular structures. A stoichiometric amount of VP2 allowed the assembly of VP1 pentamers into spherical particles in a pH range of 7.0 to 4.0. Electron microscopy observation, sucrose gradient sedimentation analysis, and antibody accessibility tests showed that VP2 is incorporated into VP1 particles. The functional domains of VP2 important for VP1 binding and for enhancing VP1 assembly were further explored with a series of VP2 deletion mutants. VP3 also enhanced VP1 assembly, and a region common to VP2 and VP3 (amino acids 119-272) was required to promote VP1 pentamer assembly. These results are relevant for controlling recombinant capsid formation in vitro, which is potentially useful for the in vitro development of SV40 virus vectors.

Animals↗

Cerebrospinal fluid S-100B concentrations in normal and diseased cattle.

We measured the concentrations of S-100B, a marker protein used in humans to detect brain damage, in the cerebrospinal fluid (CSF) of clinically normal cattle (n=15, mean age +/- SD: 31.8 +/- 37.5 months) and of cattle with various inflammatory disorders (n=43, 70.6 +/- 31.9 months). The mean +/- SD CSF S-100B level was 2.9 +/- 1.6 ng/ml in the normal group and 7.0 +/- 7.4 ng/ml in the diseased group. Thirteen diseased cattle that had developed no obvious neurological signs showed abnormally high S-100B concentrations (> 8.0 ng/ml), whereas the two cattle with neurological disorders did not. No particular disease could be related to the S-100B rise. Therefore, it remains inconclusive whether measurement of CSF S-100B concentration is useful in veterinary neurological diagnosis.

Age Factors↗

A new method for fish leucocyte counting and partial differentiation by flow cytometry.

A simple and rapid method for analysis of fish blood cells is presented. Carp (Cyprinus carpio) blood was diluted 200 times with Hanks' solution containing 1 microg/ml of DiOC6(3) which is a fluorescent, lipophilic dye. After staining for 10 min, the blood cells were measured by a flow cytometer (FACS). Several blood cell populations were identified by different FL-1 (green fluorescence), FSC (forward scatter), and SSC (side scatter) properties. FL-1 v. SSC or FSC v. SSC dot-plot of stained blood cells displayed five separate cell populations: erythrocytes: a mixture of thrombocytes plus lymphocytes; monocytes; neutrophils; and basophils. The number of each type of blood cell counted by the FACS was in good agreement with those counted microscopically.

Animals↗