Physarum polycephalum macroplasmodium exhibits countermeasures against TiO nanoparticle toxicity: A physiological, biochemical, transcriptional, and metabolic perspective.

Concerns about the environmental and human health implications of TiO nanoparticles (nTiO) are growing with their increased use in consumer and industrial products. Investigations of the underlying molecular mechanisms of nTiO tolerance in organisms will assist in countering nTiO toxicity. In this study, the countermeasures exhibited by the slime mold Physarum polycephalum macroplasmodium against nTiO toxicity were investigated from a physiological, transcriptional, and metabolic perspective.

Nano-sized TiO (nTiO) induces metabolic perturbations in Physarum polycephalum macroplasmodium to counter oxidative stress under dark conditions.

Nano-sized TiO (nTiO) exerts an oxidative effect on cells upon exposure to solar or UV irradiation and ecotoxicity of the nTiO is an urgent concern. Little information is available regarding the effect of TiO on cells under dark conditions. Metabolomics is a unique approach to the discovery of biomarkers of nTiO cytotoxicity, and leads to the identification of perturbed metabolic pathways and the mechanism underlying nTiO toxicity.

Identification of a novel PSR as the substrate of an SR protein kinase in the true slime mold.

Here, a novel cDNA encoding a serine/arginine (SR)-rich protein, designated PSR, was isolated from the true slime mold Physarum polycephalum and expressed in Escherichia coli. The deduced amino acid (aa) sequence reveals that PSR contains RS repeats at its C-terminus, similar to the conventional PSRPK substrate ASF/SF2. To study the novel protein, we generated a variety of mutant constructs by PCR and site-directed mutagenesis.

Expression inhibition of multidrug resistance-associated protein (MRP1) by multi-ribozyme expression system in HEK293 cells.

To study application of multi-ribozyme expression system on expression inhibition of multidrug resistance-associated protein (MRP1) in HEK293 cells, the multi-ribozyme expression system containing 20 cis-acting ribozymes for self-cleavage and 10 trans-acting ribozymes for targeting to MRP1 gene specific site were constructed. HEK293 cells cotransfected multi-ribozyme expression system with MRP1 target gene or full length of MRP1 gene respectively were analyzed by RT-PCR, Western blot analysis and MTT assay. The results showed that multi-ribozyme systems were able to dramatically decrease fluorescent fusion protein expression in HEK293 cells.

[Expression silence of Physarum polycephalum serine/arginine protein kinase by small interfering RNA].

Serine/arginine protein kinases are specific kinase family for phosphorylating SR protein regulating alternative splicing of SR protein and its distribution, localization in the nucleus. However, it is unclear how Physarum Polycephalum Serine/Arginine Protein Kinase(PSRPK) functions in the cells. In order to study its function, Oligonucleotides for transcribing siRNAs were designed and inserted into pSIREN-RetroQ vector to construct pSIREN-PSRPK-1, pSIREN-PSRPK-2, pSIREN-PSRPK-3, pSIREN-PSRPK-4, pSIREN-PSRPK-5 for expressing siRNAs targeting at PSRPK, as well as the negative control pSIREN-PSRPK-Neg.

[The characteristics of PSCL32.5 protein from Physarum polycephalum and the variation of the content through cell cycle].

Crude fraction of Arg/Ser-rich proteins (SR proteins) were isolated from plasmodia of Physarum polycephalum and immunoassayed by western blot with a monoclonal antibody against SC35 protein from HeLa cell. Two polypeptides were detected by the antibody, suggesting that they were SCL(SC35-like) proteins. The SCL proteins have their mass weight of 32.

[Preparation and preliminary identification of the monoclonal antibody to bovine bFGF].

Aim: To prepare mAb against bovine bFGF and identify their Ig subgroups so as to establish an ELISA for detection of bFGF level.

Methods: BALB/c mice were immunized by recombinant bovine bFGF. Hybridoma cell lines which could stably secret the monoclonal antibodies to bFGF were established by cell fusion technique, and their related characteristics were identified.

[Isolation and identification of SARS-coronavirus in nasal and throat swabs collected from clinically diagnosed SARS patients].

Objective: To isolate and identify SARS-coronavirus in nasal and throat swabs collected from clinically diagnosed severe acute respiratory syndrome (SARS) patients.

Methods: Nasal and throat swab specimens were inoculated onto well of 24-well plate containing confluent monolayers of Vero and MRC-5 cells. Isolates were identified with serology, electron microscopy and genome sequence.