Figure 7

Schematic model of putative role of PfSR25 in activation of Ca²⁺ signaling and stress survival: When P. falciparum parasite is exposed to low K⁺ environment, activation of PfSR25 leads to PLC-mediated intracellular Ca²⁺ release from ER, which further activates downstream Ca²⁺-mediated signaling pathways such as PKB²⁵ or CDPK1²⁶. On the other hand, PfSR25 ⁻ parasites display different sensitivity to the antimalarial drugs chloroquine, piperaquine and lumefantrine⁴³ when compared to wt parasite. On top of that, recovery of wt parasite after SNP-mediated stress is higher in comparison to PfSR25 ⁻. PLC - phospholipase C; ER – endoplasmic reticulum; Ca²⁺ - calcium ion; THG – thapsigargin; CPA – cyclopiazonic acid; SERCA – sarcoendoplasmic reticulum Ca²⁺ ATPases; PKB – protein kinase B; CDPK1 - calcium-dependent protein kinase 1; DV- digestive vacuole; Hz – hemozoin; SNP - sodium nitroprusside.