ApiLoc - A database of published protein sub-cellular localisation in Apicomplexa

version 3 (curated until May 28, 2011)

Monoclonal antibody against the Plasmodium falciparum chitinase, PfCHT1, recognizes a malaria transmission-blocking epitope in Plasmodium gallinaceum ookinetes unrelated to the chitinase PgCHT1.

Langer, R. C., Li, F., Popov, V., Kurosky, A., Vinetz, J. M. (2002 Mar, Infect Immun)

To initiate invasion of the mosquito midgut, Plasmodium ookinetes secrete chitinases that are necessary to cross the chitin-containing peritrophic matrix en route to invading the epithelial cell surface. To investigate chitinases as potential immunological targets of blocking malaria parasite transmission to mosquitoes, a monoclonal antibody (MAb) was identified that neutralized the enzymatic activity of the sole chitinase of Plasmodium falciparum, PfCHT1, identified to date. This MAb, designated 1C3, previously shown to react with an apical structure of P. falciparum ookinetes, also reacts with a discrete apical structure of P. gallinaceum ookinetes. In membrane feeding assays, MAb 1C3 markedly inhibited P. gallinaceum oocyst development in mosquito midguts. MAb 1C3 affinity isolated an approximately 210-kDa antigen which, under reducing conditions, became a 35-kDa antigen. This isolated 35-kDa protein cross-reacted with an antiserum raised against a synthetic peptide derived from the P. gallinaceum chitinase active site, PgCHT1, even though MAb 1C3 did not recognize native or recombinant PgCHT1 on Western blot. Therefore, this affinity-purified 35-kDa antigen appears similar to a previously identified protein, PgCHT2, a putative second chitinase of P. gallinaceum. Epitope mapping indicated MAb 1C3 recognized a region of PfCHT1 that diverges from a homologous amino acid sequence conserved within sequenced chitinases of P. berghei, P. yoelii, and P. gallinaceum (PgCHT1). A synthetic peptide derived from the mapped 1C3 epitope may be useful as a component of a subunit transmission-blocking vaccine.

PubMed: 11854247, full text

Localisation information

No assigned gene identifier (WARP, CHT2) Nothing has been found

Experimental localisation: apical during ookinete, microneme during ookinete, conoid collar during ookinete, extracellular during ookinete
  • Species: Plasmodium gallinaceum
  • Quote inferring localisation: "Labeling of the 1C3 epitope is present within micronemes, the apical tip, laterally along the conoid collar (arrows), and extracellularly."
  • Microscopy type: light, EM
  • Microscopy method: monoclonal antibody
  • Strain: 8A
  • Gene model mapping comments: sequence does not appear to be available in GenBank, or in the publication, except the protein coding
  • Localisation record: apical and microneme and conoid collar and extracellular during ookinete
  • Comment: not sequenced in publication, and blasting epitope LYDSYAYYGKKYD against the incomplete P. gallinaceum genome only gives a single hit. Blasting the epitope against P. falciparum gives PfCHT1 as the only hit