A Major Role for the Plasmodium falciparum ApiAP2 Protein PfSIP2 in Chromosome End Biology
Figure 2
PfSIP2-N localizes to P. falciparum chromosome end clusters.
(A) IFA detects discrete perinuclear PfSIP2-N-HA signals in late trophozoites (LT) and early (ES) and late (LS) schizont stage 3D7/SIP2-N-HA parasites. The expression cassette is schematically depicted on the left. (B) Co-localisation of PfSIP2-N with PfHP1-containing subtelomeric heterochromatin in late trophozoites (LT) and early (ES) and late (LS) schizonts in the double transgenic parasite line 3D7/SIP2-N-HA/HP1-Ty (over-expressing both proteins as epitope-tagged versions simultaneously). Expression cassettes are schematically depicted on the left. (C) Targeted ChIP-qPCR analysis demonstrates the specific binding of PfSIP2-N-HA to SPE2 upstream of upsB var gene PFL0005w in 3D7/SIP2-N-HA. Fold enrichment of cross-linked PfSIP2-N-HA-associated chromatin was determined for five regions across the PFL0005w locus. Values represent the mean of three independent experiments (error bars indicate the standard deviation). The location of the SPE2 repeat array and the positions of qPCR primers are indicated by nucleotide positions with respect to the ATG start codon. 3D7 wild-type parasites were used as negative control.
