PF3D7_0424400 surface-associated interspersed protein 4.2 (SURFIN 4.2)

SURFINs expressed in 3D7S8 and FCR3S1.2 are cotransported with PfEMP1 to the host PM. (A) Indirect immunofluorescence assay (IFA) on air-dried monolayers of 3D7S8 IEs at various stages of maturation with SURFIN4.2-directed anti-S1.3 antibodies. Antibodies detected SURFIN4.2 in 25% of examined parasites at 24 h in dot-like transport vesicles outside the parasitophorous vacuole. (B) Dual localization of TRITC-labeled SURFIN4.2 (red) and Alexa 488–labeled PfEMP1 (green) showed that SURFIN4.2 and PfEMP1 are colocalized in cytosolic structures. An expressed SURFIN was detected in 90% of trophozoite-stage FCR3S1.2 IEs and colocalized with PfEMP1 in large multimeric vesicles. Dashed circles indicate the area of the IE. (C) Immunoelectron microscopy studies on 3D7S8 and FCR3S1.2 IEs. SURFIN detected with either anti-S1.3 serum or affinity purified anti-S1.4 immunoglobulins is present in the PM, as well as in the erythrocyte cytosol associated with Maurer’s clefts (MC) as indicated by arrows. Bars: (A and B), 2 mm; (C), 0.5 mm.

Winter G, Kawai S, Haeggström M, Kaneko O, von Euler A, Kawazu S, Palm D, Fernandez V, Wahlgren M. SURFIN is a polymorphic antigen expressed on Plasmodium falciparum merozoites and infected erythrocytes. J Exp Med. 2005 201:1853-63.

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