Lacking catalase, a protistan parasite draws on its photosynthetic ancestry to complete an antioxidant repertoire with ascorbate peroxidase.

ABSTRACT:

Background

Antioxidative enzymes contribute to a parasite's ability to counteract the host's intracellular killing mechanisms. The facultative intracellular oyster parasite, Perkinsus marinus, a sister taxon to dinoflagellates and apicomplexans, is responsible for mortalities of oysters along the Atlantic coast of North America. Parasite trophozoites enter molluscan hemocytes by subverting the phagocytic response while inhibiting the typical respiratory burst. Because P. marinus lacks catalase, the mechanism(s) by which the parasite evade the toxic effects of hydrogen peroxide had remained unclear. We previously found that P. marinus displays an ascorbate-dependent peroxidase (APX) activity typical of photosynthetic eukaryotes. Like other alveolates, the evolutionary history of P.

SUBMITTER: Schott EJ 

PROVIDER: S-EPMC6642578 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature