Apicomplexan C-Mannosyltransferases Modify Thrombospondin Type I-containing Adhesins of the TRAP Family

作者：Hoppe Carolin M; Albuquerque Wendt Andreia; Bandini Giulia; Leon Deborah R; Shcherbakova Aleksandra; Buettner Falk F R; Izquierdo Luis; Costello Catherine E; Bakker Hans; Routier Francoise H^*

来源：Glycobiology, 2018, 28(5): 333-343.

DOI：10.1093/glycob/cwy013

• apicomplexa
• C-mannosylation
• thrombospondin type 1 repeat

In many metazoan species, an unusual type of protein glycosylation, called C-mannosylation, occurs on adhesive thrombospondin type 1 repeats (TSRs) and type I cytokine receptors. This modification has been shown to be catalyzed by the Caenorhabditis elegans DPY-19 protein and orthologues of the encoding gene were found in the genome of apicomplexan parasites. Lately, the micronemal adhesin thrombospondin-related anonymous protein (TRAP) was shown to be C-hexosylated in Plasmodium falciparum sporozoites. Here, we demonstrate that also the micronemal protein MIC2 secreted by Toxoplasma gondiitachyzoites is C-hexosylated. When expressed in a mammalian cell line deficient in C-mannosylation, P. falciparum and T. gondii Dpy19 homologs were able to modify TSR domains of the micronemal adhesins TRAP/MIC2 family involved in parasite motility and invasion. In vitro, the apicomplexan enzymes can transfer mannose to a WXXWXXC peptide but, in contrast to C. elegans or mammalian C-mannosyltransferases, are inactive on a short WXXW peptide. Since TSR domains are commonly found in apicomplexan surface proteins, C-mannosylation may be a common modification in this phylum.

• 出版日期2018-5