Wnt-3a-dependent cell motility involves RhoA activation and is specifically regulated by dishevelled-2.

Wnts stimulate cell migration, although the mechanisms responsible for this effect are not fully understood. To investigate the pathways that mediate Wnt-dependent cell motility, we treated Chinese hamster ovary cells with Wnt-3a-conditioned medium and monitored changes in cell shape and movement. Wnt-3a induced cell spreading, formation of protrusive structures, reorganization of stress fibers and migration.

Secreted frizzled-related protein-1 binds directly to Wingless and is a biphasic modulator of Wnt signaling.

Secreted Frizzled-related protein-1 (sFRP-1) contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzleds. To facilitate the biochemical and biological analysis of sFRP-1, we developed a mammalian recombinant expression system that yields approximately 3 mg of purified protein/liter of conditioned medium. Using this recombinant protein, we demonstrated that sFRP-1 and Wg (wingless) interact in enzyme-linked immunosorbent and co-precipitation assays.

Chaperone-mediated reduction of RepA dimerization is associated with RepA conformational change.

RepA, the initiator protein of plasmid P1, binds to multiple sites (iterons) in the origin. The binding normally requires participation of chaperones, DnaJ, DnaK and GrpE. When purified, RepA appears dimeric and is inactive in iteron binding.

Marked sequence diversity in the putative envelope proteins of hepatitis C viruses.

The nucleotide sequences of cDNAs (414 base pairs) encoding parts of putative envelope proteins (gp35 and gp70) of 40 isolates of hepatitis C virus (HCV-J) derived from 30 independent plasma or liver specimens from Japanese patients (13 with chronic hepatitis, 14 with hepatocellular carcinoma and 3 hemophiliacs who had received imported clotting factors), were analyzed using the polymerase chain reaction. Approximately 29-38% of the nucleotide sequences of the HCV-J isolates examined differed from those of isolates from the United States (HCV-US). Furthermore, 12-24% and 8-17% sequence diversities were found within the isolates of HCV-J and HCV-US, respectively.

Detection of hepatitis C virus infection by enzyme-linked immunosorbent assay system using core protein expressed in Escherichia coli.

Enzyme-linked immunosorbent assay of the core protein of hepatitis C virus (HCV) expressed in E. coli led to detection of the antibody against this virus in patients with chronic hepatitis. Some of the negative results obtained using a different viral protein became positive with this E.