Heterotrophy in dinoflagellates: components of endocytosis molecular machinery in Prorocentrum cordatum and Amphidinium carterae transcriptomes

Summary Heterotrophy appears to be a common and widely adopted strategy among dinoflagellates, even in predominantly photosynthetic species. To elucidate the mechanisms of switching between various trophic modes in primarily mixotrophic protists, we need the information about molecular machinery providing the uptake of nutrients of different nature. Here, we analyzed transcriptomic data available for two marine mixotrophic dinoflagellates belonging to the phylogenetically distant groups – Prorocentrum cordatum and Amphidinium carterae . This study uncovered homologs of proteins involved in endocytosis and phagosome formation, including epsin, coronin, clathrin light and heavy chains, adaptor protein complex 2 and dynamin. The enzymes, acting in the lysosomal degradation, and small GTPases regulating vesicle transport, maturation and recycling were also detected in these organisms. We provide a generalized scheme of endocytosis pathways, which includes proteins revealed in the course of this study and identified by other authors.