O-fucosylated glycoproteins form assemblies in close proximity to the nuclear pore complexes of Toxoplasma gondii

Toxoplasma gondii is an intracellular parasite that causes disseminated infections in fetuses and immunocompromised individuals. Although gene regulation is important for parasite differentiation and pathogenesis, little is known about protein organization in the nucleus. Here we show that the fucose-binding Aleuria aurantia lectin (AAL) binds to numerous punctate structures in the nuclei of tachyzoites, bradyzoites, and sporozoites but not oocysts. AAL also binds to Hammondia and Neospora nuclei but not to more distantly related apicomplexans. Analyses of the AAL-enriched fraction indicate that AAL binds O-linked fucose added to Ser/Thr residues present in or adjacent to Ser-rich domains (SRDs). Sixty-nine Ser-rich proteins were reproducibly enriched with AAL, including nucleoporins, mRNA-processing enzymes, and cell-signaling proteins. Two endogenous SRDs-containing proteins and an SRD-YFP fusion localize with AAL to the nuclear membrane. Superresolution microscopy showed that the majority of the AAL signal localizes in proximity to nuclear pore complexes. Host cells modify secreted proteins with O-fucose; here we describe the O-fucosylation pathway in the nucleocytosol of a eukaryote. Furthermore, these results suggest O-fucosylation is a mechanism by which proteins involved in gene expression accumulate near the NPC.

Aleuria aurantia - indole metabolites of fruit bodies, mycelial culture and culture medium

The aim of present study was to investigate and compare indole metabolites of fruit bodies, mycelium cultivated <i>in vitro</i> and culture medium of the fungus <i>Aleuria aurantia</i> (Fr.) Fuck. By use of a number of chromatographic and spectroscopic methods several indole metabolites have been detected and identified among other the 3-indolebutyric acid was produced and extracted to the culture medium. Furthermore 3-indoleatonitrile and tryptophane degradative products have been found both in fruit bodies and mycelium.

Fucose and Sialic Acid Expressions in Human Seminal Fibronectin andα1-Acid Glycoprotein Associated with Leukocytospermia of Infertile Men

Introduction: The aim of this study was to compare fucose and sialic acid residue expression on fibronectin andα1-acid glycoprotein in the seminal plasma of men suspected of infertility and suffering from leukocytospermia.Subjects and methods: Seminal ejaculates were collected from 27 leukocytospermic and 18 healthy, normozoospermic men. The relative degree of fucosylation and sialylation of fibronectin andα1-acid glycoprotein was estimated by ELISA using fucose and sialic acid specific lectins fromAleuria aurantia, Lotus tetragonolobus, andUlex europaeusas well asMaackia amurensisandSambucus nigra, respectively.Results: Leukocytospermic seminal fibronectin, in comparison with fibronectin of normal fertile group, showed lower relative reactivity with AAL, LTA and UEA, and higher reactivity with MAA and SNA, while the AGP of the leukocytospermic group was less reactive with AAL, and the relative reactivity with LTA and MAA was significantly higher. Fibronectin andα1-acid glycoprotein reactivity with UEA and MAA showed high positive correlations.Discussion: Leukocytospermia was associated with the alterations of terminal monosaccharide expression in human seminal fibronectin andα1-acid glycoprotein. The increase of sialyl-Lewisxantigen inα1-acid glycoprotein can be used as a marker of genital tract inflammation manifested by leukocytospermia.