ROP GTPase regulation of pollen tube growth through the dynamics of tip-localized F-actin.

Pollen tubes expand by tip growth and extend directionally toward the ovule to deliver sperms during pollination. They provide an excellent model system for the study of cell polarity control and tip growth, because they grow into uniformly shaped cylindrical cells in culture. Mechanisms underlying tip growth are poorly understood in pollen tubes.

[The study of aggregate of the ORF2 peptide of hepatitis E virus expressed in Escherichia coli].

A fragment of hepatitis E virus open reading frame-2(ORF2), located from amino acid residues 394 to 604, was expressed in E. coli. The recombinant protein NE2 was found to form homodimer mostly in SDS-PAGE, which can be dissociated to monomers when treated with urea, and it was recognized more strongly in its dimeric form than the monomer by HEV reactive human serum in Western blotting.

Cloning, Sequencing and Expression of the atpE Gene of Broad Bean Chloroplast.

The ninth KpnI fragment (about 4.0 kb) of broad bean chloroplast DNA contains the entire chloroplast atpE gene and atpB gene. This fragment was inserted into the pUC18 polylinker region, yielding plasmid pUK1.

Involvement of TRAF4 in oxidative activation of c-Jun N-terminal kinase.

We previously found that the angiogenic factors TNFalpha and HIV-1 Tat activate an NAD(P)H oxidase in endothelial cells, which operates upstream of c-Jun N-terminal kinase (JNK), a MAPK involved in the determination of cell fate. To further understand oxidant-related signaling pathways, we screened lung and endothelial cell libraries for interaction partners of p47(phox) and recovered the orphan adapter TNF receptor-associated factor 4 (TRAF4). Domain analysis suggested a tail-to-tail interaction between the C terminus of p47(phox) and the conserved TRAF domain of TRAF4.

TNFalpha activates c-Jun amino terminal kinase through p47(phox).

Reactive oxygen intermediates have been implicated in the transduction of TNFalpha signals, although the source of such oxidants has not been established. We found that activation of ECV-304 cells by TNFalpha was accompanied by a transient burst of oxidants and activation of JNK, both of which were suppressed by two distinct inhibitors of the phagocyte NADPH oxidase and the thiol antioxidant N-acetyl cysteine (NAC). We cloned partial and full-length cDNA sequences from ECV-304 cells and human umbilical vein endothelial cells (HUVEC), respectively, for p47(phox), demonstrating that these nonphagocytic cells express this adapter protein known to specifically initiate assembly of the NADPH oxidase in professional phagocytes.