Combining IP(3) affinity chromatography and bioinformatics reveals a novel protein-IP(3) binding site on Plasmodium falciparum MDR1 transporter

Intracellular Ca(2+) mobilization induced by second messenger IP(3) controls many cellular events in most of the eukaryotic groups. Despite the increasing evidence of IP(3)-induced Ca(2+) in apicomplexan parasites like Plasmodium, responsible for malaria infection, no protein with potential function as an IP(3)-receptor has been identified. The use of bioinformatic analyses based on previously known sequences of IP(3)-receptor failed to identify potential IP(3)-receptor candidates in any Apicomplexa. In this work, we combine the biochemical approach of an IP(3) affinity chromatography column with bioinformatic meta-analyses to identify potential vital membrane proteins that present binding with IP(3) in Plasmodium falciparum. Our analyses reveal that PF3D7_0523000, a gene that codes a transport protein associated with multidrug resistance as a potential target for IP(3). This work provides a new insight for probing potential candidates for IP(3)-receptor in Apicomplexa.