A cytochrome b561 with ferric reductase activity from the parasitic blood fluke, Schistosoma japonicum.

• Published in: PLoS Neglected Tropical Diseases
• Main Authors: Amber Glanfield, Donald P McManus, Danielle J Smyth, Erica M Lovas, Alex Loukas, Geoffrey N Gobert, Malcolm K Jones
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2010
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic
• Online Access: https://doi.org/10.1371/journal.pntd.0000884; https://doaj.org/article/d7b2ea59f98d4c45af8f16a9ab7e5e4d

BACKGROUND: Iron has an integral role in numerous cellular reactions and is required by virtually all organisms. In physiological conditions, iron is abundant in a largely insoluble ferric state. Ferric reductases are an essential component of iron uptake by cells, reducing iron to the soluble ferrous form. Cytochromes b561 (cyts-b561) are a family of ascorbate reducing transmembrane proteins found in most eukaryotic cells. The identification of the ferric reductase duodenal cytochrome b (dcytb) and recent observations that other cyts-b561 may be involved in iron metabolism have opened novel perspectives for elucidating their physiological function. METHODOLOGY/PRINCIPAL FINDINGS: Here we have identified a new member of the cytochrome b561 (Sjcytb561) family in the pathogenic blood fluke Schistosoma japonicum that localises to the outer surface of this parasitic trematode. Heterologous expression of recombinant Sjcyt-b561 in a Saccharomyces cerevisiae mutant strain that lacks plasma membrane ferrireductase activity demonstrated that the molecule could rescue ferric reductase activity in the yeast. SIGNIFICANCE/CONCLUSIONS: This finding of a new member of the cytochrome b561 family further supports the notion that a ferric reductase function is likely for other members of this protein family. Additionally, the localisation of Sjcytb561 in the surface epithelium of these blood-dwelling schistosomes contributes further to our knowledge concerning nutrient acquisition in these parasites and may provide novel targets for therapeutic intervention.