AUTHOR=Vasilev Jana , Mix Ann-Kathrin , Heimerl Thomas , Maier Uwe G. , Moog Daniel 

TITLE=Inferred Subcellular Localization of Peroxisomal Matrix Proteins of Guillardia theta Suggests an Important Role of Peroxisomes in Cryptophytes

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.889662

DOI=10.3389/fpls.2022.889662

ISSN=1664-462X

ABSTRACT=<p>Peroxisomes participate in several important metabolic processes in eukaryotic cells, such as the detoxification of reactive oxygen species (ROS) or the degradation of fatty acids by β-oxidation. Recently, the presence of peroxisomes in the cryptophyte <italic>Guillardia theta</italic> and other “chromalveolates” was revealed by identifying proteins for peroxisomal biogenesis. Here, we investigated the subcellular localization of candidate proteins of <italic>G. theta</italic> in the diatom <italic>Phaeodactylum tricornutum</italic>, either possessing a putative peroxisomal targeting signal type 1 (PTS1) sequence or factors lacking a peroxisomal targeting signal but known to be involved in β-oxidation. Our results indicate important contributions of the peroxisomes of <italic>G. theta</italic> to the carbohydrate, ether phospholipid, nucleotide, vitamin K, ROS, amino acid, and amine metabolisms. Moreover, our results suggest that in contrast to many other organisms, the peroxisomes of <italic>G. theta</italic> are not involved in the β-oxidation of fatty acids, which exclusively seems to occur in the cryptophyte's mitochondria.</p>