Characterization of Plasmodium vivax calcium dependent protein(CDPK)

초록

Sexual stage in mosquito intestine is the most abundant physiological-biochemical phenomena in the complex malaria life cycle. In sexual stage, gametocytes secret variety biochemical signals for induction of flagellum of microgametocyte and fertilization of nucleus from microgametocyte and macrogametocyte is occurred. Calcium dependent protein kinase (CDPK) is the key regulators that mediate flagella induction from microgametocyte to fertilization with macrogametocyte in sexual stage. In P. falciparum, CDPKs have three kind isoform with similar structure and express in sexual stage. We extracted genomic DNA of Korea P. vivax strain from patients’ blood and cloned CDPK gene. PvCDPK gene is 1,762 bp of open reading frame (ORF) and deduced 587 amino acids. PvCDPK has an intron between two exons and constructs serine/threonine domain, junction domain and calmodulin like domain (EF-hand). In N-terminus, variety domains for serine/threonine and multi consensus phosphorylation sites coded protein kinase were identified. We expressed recombinant protein of about 62 kDa and measured kinase activity used Kinase-Glo Reagent (Promega). Protein kinase activity of PvCDPK proportionally increased the recombinant protein, ATP and Ca2+ concentration, and gradually decreased the EGTA, Ca2+ chelator. PvCDPK activity depended on ATP and Ca2+ ion and inhibited by EGTA. These data suggest that PvCDPK is functional serine/threonine kinase, regulated by calcium, and may have a role in Ca2+-mediated signaling in P. vivax.