PfAMA1 translocation and egress in 3D7-PfCDPK5DDKnL parasites. (A) SR-SIM IFA of [-] Shld-1 schizonts or [+] Shld-1 schizonts probed with anti-PfAMA1 antibodies. Representative parasites with micronemal and translocated PfAMA1 are shown. Bars, 2 mm. Synchronized 3D7-PfCDPK5DDKnL ring-stage parasites were maintained in the presence and absence of Shld-1 until 46 h.p.i., E64 was added, and cultures were incubated for an additional 6 h. Harvested schizonts were evaluated for the localization of PfAMA1 (A). In schizonts grown in the presence of Shld-1 ([+]SR-SIM IFAs performed on [-] Shld-1 and [+] Shld-1 3D7-PfCDPK5DDKnL schizonts demonstrating that the localization of PfEBA175 was not different in pre- and post-“egress trigger” [-] Shld-1 schizonts or in [+] Shld-1 schizonts Shld-1 schizonts), 37% +- 8% had micronemal PfAMA1, and 63% +- 8% showed plasma membrane localization. In sharp contrast, 92% +- 2% of the schizonts grown in the absence of Shld-1 ([+] Shld-1 schizonts) had micronemal PfAMA1, and only 8% +- 2% demonstrated plasma membrane localization . It is important to note that the 3D7-PfCDPK5DDKnL parasites allow knockdown but do not completely knock out PfCDPK5. Thus, we find rare [-] Shld-1 schizonts with plasma membrane-localized PfAMA1. These [-] Shld-1 schizonts with translocated PfAMA1 may be from residual low levels of PfCDPK5 or from a less utilized PfCDPK5-independent pathway.
Absalon S, Blomqvist K, Rudlaff RM, DeLano TJ, Pollastri MP, Dvorin JD. Calcium-Dependent Protein Kinase 5 Is Required for Release of Egress-Specific Organelles in Plasmodium falciparum. mBio. 2018 Feb 27;9(1):e00130-18.
Other associated proteins
|PF3D7_0731500||erythrocyte binding antigen-175|
|PF3D7_1337800||calcium-dependent protein kinase 5, CDPK5|