D purification of recombinant proteinsThe coding region of proteins 14-3-3I (PF3D7_0818200) and 14-3-3II (PF3D7_1362100) were GST-tagged at N-terminal by cloning into pGEX vector. Primer pair used for 14-3-3I were: f69GSTn: CGCGGGATCCATGGCAACATCTGA-AGAATTAAAAC and r69GSTn: GCGCGAATTCTCATTCTAATCCTTCGTCTTTTGAT and that for 14-3-3II were: f309GSTn: GCGCGGATCCATGAATCAATATATTGATAACGATATTTC and r309GSTn: GCGCGAATTCTTATGTATGAGTACTATTCATAATGTC. The resulting constructs were named GST-14-3-3I and GST-14-3-3II respectively and were transformed into the E. coli strain BL21. Bacteria expressing the GST-tagged version of the 204-bp chromo-domain of heterochromatin protein 1 (GST-HP1CD) was kindly supplied by Dr. Rosaura Hernandez-Rivas [26]. Expression of GST-fusion proteins was induced with 0.50 mM IPTG at 37uC for GST-14-33I and GST-14-3-3II and at 30uC for GST-HP1CD for 6 hours. All the GST-fusion proteins were purified using glutathione sepharose beads (GE Healthcare Life Sciences). The purity of the eluted proteins was checked by standard SDS-PAGE and coomassie staining.Materials and Methods Histone ExtractionHistones were obtained by acid extraction and high-salt extraction techniques from unsynchronized culture of 3D7 strain parasites [24]. Parasites were grown in human blood that had been washed to deplete white blood cell contamination. Complete protease inhibitor (PI) [Roche, 11697498001] and complete phosphatase inhibitor (PPI) [Roche, 4906845001] were used during all steps, starting from collection of infected red blood cells (iRBC) through extraction of histones. All steps were GNF-7 biological activity performed at 4uC to minimize enzymatic activities that could potentially interfere with PTMs. For both types of extraction, 6 ml of iRBC of 5 parasitemia were collected and were lysed on ice using 0.15 saponin. The parasites were then washed three times in ice cold PBS until the supernatant was clear and no blood was observed in the parasite pellet. The resulting pellet was further treated with 0.06 saponin to remove any leftover blood contamination and washed three more times in ice cold PBS. The resulting parasite pellet was differentially treated as follows for acid and high salt extraction methods respectively (Figure 1). Red blood cells were obtained from the Etablissement Francais du ?Sang of Necker hospital, Paris, under agreement with Institut Pasteur, and following guidelines for informed consent of Salmon calcitonin site donors for the use of blood or its derivatives for research purposes. Acid Extraction of Histones. Histones were acid extracted using the Active Motif histone purification mini kit (cat. no. 40026) following the manufacturer’s recommendations with slight modifications. Briefly, the parasite pellet was resuspended in 10 ml of ice cold Histone Extraction Buffer and sonicated for 5 minutes (30 1527786 seconds ON/OFF cycle) at 4uC using Bioruptor UCD-200 (Diagenode). The pellets were incubated overnight at 4uC to extract total histones. Cellular debris 11967625 was removed by centrifugation at 160006g at 4uC for 10 minutes. The supernatant containing crude histones was applied to a sulfopropyl (SP) resin column supplied with the kit to bind histones. The column was next washed with Histone Wash Buffer and histones were eluted using Histone Elution Buffer.Production of anti-14-3-3 antibodyRecombinant GST-14-3-3I protein was purified as above to produce rat anti-14-3-3I antibodies according to the standard protocols of Genscript (USA).Western Blot (WB) AnalysisExtracted total hi.D purification of recombinant proteinsThe coding region of proteins 14-3-3I (PF3D7_0818200) and 14-3-3II (PF3D7_1362100) were GST-tagged at N-terminal by cloning into pGEX vector. Primer pair used for 14-3-3I were: f69GSTn: CGCGGGATCCATGGCAACATCTGA-AGAATTAAAAC and r69GSTn: GCGCGAATTCTCATTCTAATCCTTCGTCTTTTGAT and that for 14-3-3II were: f309GSTn: GCGCGGATCCATGAATCAATATATTGATAACGATATTTC and r309GSTn: GCGCGAATTCTTATGTATGAGTACTATTCATAATGTC. The resulting constructs were named GST-14-3-3I and GST-14-3-3II respectively and were transformed into the E. coli strain BL21. Bacteria expressing the GST-tagged version of the 204-bp chromo-domain of heterochromatin protein 1 (GST-HP1CD) was kindly supplied by Dr. Rosaura Hernandez-Rivas [26]. Expression of GST-fusion proteins was induced with 0.50 mM IPTG at 37uC for GST-14-33I and GST-14-3-3II and at 30uC for GST-HP1CD for 6 hours. All the GST-fusion proteins were purified using glutathione sepharose beads (GE Healthcare Life Sciences). The purity of the eluted proteins was checked by standard SDS-PAGE and coomassie staining.Materials and Methods Histone ExtractionHistones were obtained by acid extraction and high-salt extraction techniques from unsynchronized culture of 3D7 strain parasites [24]. Parasites were grown in human blood that had been washed to deplete white blood cell contamination. Complete protease inhibitor (PI) [Roche, 11697498001] and complete phosphatase inhibitor (PPI) [Roche, 4906845001] were used during all steps, starting from collection of infected red blood cells (iRBC) through extraction of histones. All steps were performed at 4uC to minimize enzymatic activities that could potentially interfere with PTMs. For both types of extraction, 6 ml of iRBC of 5 parasitemia were collected and were lysed on ice using 0.15 saponin. The parasites were then washed three times in ice cold PBS until the supernatant was clear and no blood was observed in the parasite pellet. The resulting pellet was further treated with 0.06 saponin to remove any leftover blood contamination and washed three more times in ice cold PBS. The resulting parasite pellet was differentially treated as follows for acid and high salt extraction methods respectively (Figure 1). Red blood cells were obtained from the Etablissement Francais du ?Sang of Necker hospital, Paris, under agreement with Institut Pasteur, and following guidelines for informed consent of donors for the use of blood or its derivatives for research purposes. Acid Extraction of Histones. Histones were acid extracted using the Active Motif histone purification mini kit (cat. no. 40026) following the manufacturer’s recommendations with slight modifications. Briefly, the parasite pellet was resuspended in 10 ml of ice cold Histone Extraction Buffer and sonicated for 5 minutes (30 1527786 seconds ON/OFF cycle) at 4uC using Bioruptor UCD-200 (Diagenode). The pellets were incubated overnight at 4uC to extract total histones. Cellular debris 11967625 was removed by centrifugation at 160006g at 4uC for 10 minutes. The supernatant containing crude histones was applied to a sulfopropyl (SP) resin column supplied with the kit to bind histones. The column was next washed with Histone Wash Buffer and histones were eluted using Histone Elution Buffer.Production of anti-14-3-3 antibodyRecombinant GST-14-3-3I protein was purified as above to produce rat anti-14-3-3I antibodies according to the standard protocols of Genscript (USA).Western Blot (WB) AnalysisExtracted total hi.
