Hevea brasiliensis is the main source of natural rubber. Restricted by its tropical climate conditions, the planting area in China is limited, resulted in a low self-sufficiency. Periploca sepium which can produce natural rubber is a potential substitute plant. cis-prenyltransferase (CPT), small rubber particle protein (SRPP) and rubber elongation factor (REF) are key enzymes involved in the biosynthesis of cis-1, 4-polyisoprene, the main component of natural rubber. In this study, we cloned the promoter sequences of CPT, SRPP and REF through chromosome walking strategy. The spatial expression patterns of the three promoters were analyzed using GUS (β-glucuronidase) as a reporter gene driven by the promoters through Agrobacterium-mediated genetic transformation. The results showed that GUS driven by CPT, SRPP or REF promoter was expressed in leaves and stems, especially in the leaf vein and vascular bundle. The GUS activity in stems was higher than that in leaf. This study provided a basis for analyzing the biosynthesis mechanism of natural rubber and breeding new varieties of high yield natural rubber.
Peptide Elongation Factors/genetics* ; Plant Proteins/metabolism* ; Periploca/metabolism* ; Rubber ; Plant Breeding ; Cloning, Molecular

We have used a surface plasmon resonance biosensor (SPR, BIACORE 2000) to detect antibodies against glucose 6-phosphate isomerase (GPI) in synovial fluids of rheumatoid arthritis (RA) and osteoarthritis (OA). Recombinant human GPI proteins fused with or without NusA were expressed in E. coli, purified to homogeneity and immobilized in flow cells of CM5 sensor chips. The flow cells immobilized with NusA protein or bovine serum albumin were used to monitor non-specific binding. Synovial fluid samples from RA patients showed a significantly higher level of binding to recombinant GPI proteins than samples from OA patients. Proteins which bound to the recombinant GPI proteins were confirmed to be immunoglobulin through the administration of anti-human immunoglobulin. NusA fusion protein was excellent for this assay because of a low background binding activity in the SPR analysis and its advantage of increased solubility in recombinant protein production. These results suggested a useful utilization of recombinant NusA-GPI fusion protein for the detection of autoantibodies against GPI in RA patients.
Aged ; Antibodies/*immunology ; Arthritis, Rheumatoid/*immunology ; Female ; Glucose-6-Phosphate Isomerase/genetics/*immunology/metabolism ; Human ; Male ; Middle Aged ; Osteoarthritis/immunology ; Peptide Elongation Factors/genetics/metabolism ; Recombinant Fusion Proteins/genetics/metabolism ; Surface Plasmon Resonance ; Synovial Fluid/*immunology ; Transcription Factors/genetics/metabolism

Eukaryotic elongation factor eEF-2 mediates regulatory steps important for the overall regulation of mRNA translation in mammalian cells and is activated by variety of cellular conditions and factors. In this study, eEF-2 specific, Ca2+/CaM-dependent protein kinase III (CaM PK III), also called eEF-2 kinase, was examined under oxidative stress and cell proliferation state using CHO cells. The eEF-2 kinase activity was determined in the kinase buffer containing Ca2+ and CaM in the presence of eEF-2 and [gamma-32P] ATP. The eEF-2 kinase activity in cell lysates was completely dependent upon Ca2+ and CaM. Phosphorylation of eEF-2 was clearly identified in proliferating cells, but not detectable in CHO cells arrested in their growth by serum deprivation. The content of the eEF-2 protein, however, was equivalent in both cells. Using a phosphorylation state-specific antibody, we show that oxidant such as H2O2, which triggers a large influx of Ca2+, dramatically enhances the phosphorylation of eEF-2. In addition, H2O2-induced eEF-2 phosphorylation is dependent on Ca2+ and CaM, but independent of protein kinase C. In addition, okadaic acid inhibits phosphoprotein phosphatase 2A(PP2A)-mediated eEF-2 dephosphorylation. These results may provide a possible link between the elevation of intracellular Ca2+ and cell division and suggest that phosphorylation of eEF-2 is sensitive cellular reflex on stimuli that induces intracellular Ca2+ flux.
Animal ; CHO Cells ; Ca(2+)-Calmodulin Dependent Protein Kinase/*metabolism ; Cell Division ; Cells, Cultured ; Comparative Study ; Cytosol/enzymology ; Egtazic Acid/pharmacology ; Hamsters ; Human ; Hydrogen Peroxide/*pharmacology ; Mice ; Okadaic Acid/pharmacology ; Oxidants/*pharmacology ; Peptide Elongation Factors/metabolism ; Phosphoprotein Phosphatase/metabolism ; Phosphorylation ; Polyethylene Glycols/pharmacology ; Trifluoperazine/pharmacology