Rhomboid-like proteins in Apicomplexa: phylogeny and nomenclature.

Rhomboids form a family of polytopic intramembrane serine proteases. In Toxoplasma gondii, an essential activity called microneme protein protease 1 (MPP1) cleaves secreted adhesive proteins within their transmembrane domains, at a site conserved in similar proteins of other Apicomplexa. Current evidence suggests that MPP1 is ubiquitous in the phylum and is encoded by a rhomboid gene. In this article, we present the current repertoire of rhomboid-like proteins in Apicomplexa using a nomenclature based on phylogenetic analyses.