Effect of RSA on S2 cells.

<p>(A) Control, (B) Treated cells with 0.7 µM RSA, (C) S2 cell number at time zero (at the beginning of the assay) and after 4 days incubation in the presence and absence of 0.7 µM RSA. Cell numbers increased 5.2 and 2.8 fold in control and treated cells, respectively, which showed clearly that RSA inhibited cell proliferation. (D) Concentration-response curves of S2 cells challenged with RSA for 4 days after sigmoid curve fitting in Prism v4. Cell number was measured using an MTT assay.</p

List of putatively glycosylated membrane proteins with <i>N-</i> and/or <i>O</i>-glycans located on the cell surface, identified after RSA affinity chromatography and LC-MS/MS analysis.

<p>List of putatively glycosylated membrane proteins with <i>N-</i> and/or <i>O</i>-glycans located on the cell surface, identified after RSA affinity chromatography and LC-MS/MS analysis.</p

Inhibition of RSA activity after pre-incubation of the S2 cells with different kinase inhibitors.

<p>Cells were pre-incubated with three inhibitors (individually): 10 µM of SB203580 (p38 MAP kinase inhibitor), 50 µM of PD98059 [MAP kinase, (MEK) inhibitor] and 50 µM of AG490 (JAK inhibitor) for 1 h before exposure to 0.3 µM RSA for 24 h. Values are given as means ± SEM based on two independent repetitions. Values are followed by a different letter (a-c) are significantly different (<i>post hoc</i> Tukey-Kramer test with p = 0.05).</p

Binding and uptake of lectins in <i>Drosophila melanogaster</i> S2 cells.

<p>Confocal microscopy S2 cells incubated with different lectins: S2 cells were incubated with 0.7 µM FITC-lectin for 1 h. (A) RSA- FITC (B) GNA-FITC (C) WGA-FITC and (D) PNA-FITC. Scale bars are 2.5 µM.</p

Effect of RSA to induce apoptosis in <i>Drosophila melanogaster</i> S2 cells.

<p>(A) DNA fragmentation in S2 cells. Cells were treated with 0.7 µM RSA compared to control (untreated) cells. Ten micrograms of extracted DNA was loaded on the 2% agarose gel. (B,C) Nuclear condensation assay: Upon treatment with 0.7 µM RSA, the nuclei of the S2 cells were stained with Hoechst. Typically, treated cells (C) showed a normal, non-fragmented nucleus similar to the untreated control cells (B).</p

Effect by lectins on cell proliferation in <i>Drosophila melanogaster</i> S2 cells.

<p>(A) Effect by RSA, GNA, PNA and WGA when cells were treated with lectin at 0.7 µM for 24 h. (B) Inhibitory effect of sugars on the activity of RSA on S2 cells. 0.7 µM RSA was pre-incubated with 100 µM of the specific sugar GalNAc or the non-specific sugar mannose (negative control) and PBS in the control treatments for 1 h. Then the mixtures of RSA and sugars were added to S2 cells and incubated for 24 h at 27°C. Cell proliferation was measured using an MTT assay. Data are presented as mean percentages of cell proliferation inhibition ± SE compared to the control, and based on four repeats. Values are followed by a different letter (a-c) are significantly different (<i>post hoc</i> Tukey-Kramer test with p = 0.05).</p