Immunofluorescence of PfHint-1 relative in nucleous, mitochondria and endoplasmic reticulum. (A) Cells were incubated with the nuclear probe DAPI (blue) and with the primary antibody anti-HA (1:50) to detect PfHint-1, followed by incubation with the anti- IgG rabbit-Alexa 488 secondary antibody (1:300; green). (B) Trophozoites were incubated with the mitochondrial probe Mitotracker Red (25 nM) and the primary antibody anti-HA (1:50) to detect PfHint-1, followed by incubation with anti- IgG rabbit-Alexa 488 secondary antibody (1:300; green). (C) Trophozoites were incubated with anti-HA (rabbit, 1:50) and anti-BIP (mouse, 1:500) primary antibodies, followed by incubation with the anti-IgG rabbit-Alexa 594 (1:300; red) and anti- IgG mouse-Alexa 488 (1:300, green) secondary antibodies. The colors closer to red (see color bar) indicate a higher degree of colocalization

and deconvolution is presented as maximum projection (A) or as a single slice (B, C). Scale Bar 2 mm(A,B) and 1 mm. Immunofluorescence and confocal analysis in intraerythrocytic parasites revealed that PfHint-1 is localized in tubular structures in the parasite cytoplasm that were adjacent but did not colocalize with the nucleus in rings, trophozoites and schizonts (A). Using a mitochondrial marker, we revealed that PfHint-1 is not found in parasite mitochondrion (B). By employing an antibody against an ER resident protein, anti-PfBiP, we observed that PfHint-1 and PfBiP partially colocalized (C). PfHint-1 has a predicted signal peptide which agrees with our observation that

PfHint-1 transits through the ER.

Gomes Smaul MM, Budu A, Montagna GN, Fernanda da Silva Ferrara T, El Chamy Maluf S, Bagnaresi P, Ferreira Machado MM, Bronze Dos Santos F, Ferreira de Azevedo M, Carmona AK, Gazarini ML. Plasmodium falciparum histidine triad protein and calmodulin modulates calcium homeostasis and intracellular proteolysis. Biochem Biophys Res Commun. 2018 Jun 20. [Epub ahead of print]