PfGAP45 phosphorylation is regulated via the PLC pathway in the parasite.

<p>A. [³²P] orthophosphoric acid was used to metabolically label synchronized parasites treated with 10 µM U73122 or its inactive analogue U73343, 40 µM 8-Br-cADP-ribose or 10 µM Dantrolene. Immunoprecipitation was carried out using anti-GAP45 antibody and the IPs were electrophoresed and analyzed by phosphorimaging. <i>Lower panel</i>, western blot for PfGAP45 was performed on the protein lysate used in the above immunoprecipitation experiments. B. The phosphate incorporation in PfGAP45 in experiments like the one described in panel A was assessed by either densitometric quantitation or by cerenkov counting of bands corresponding to ³²P-labelled PfGAP45, which was normalized to total PfGAP45 levels. % phosphorylation of PfGAP45 in response to various treatments is provided, the phoshorylation of DMSO treated control was taken as 100%. The mean from the densitometry measurements (black bars) for four independent experiments is shown. For two of these experiments, cerenkov counting of labeled PfGAP45 band was also performed and the average is presented as grey bars, error bars represent standard error.