d-Galactofuranose (Galf) is widely distributed in glycoconjugates of pathogenic microbes. β-d-Galactofuranosidase (Galf-ase) from Streptomyces sp. JHA19 (ORF1110) belongs to glycoside hydrolase (GH) family 2 and is the first identified Galf-specific degradation enzyme.
View Article and Find Full Text PDFIntestinal bacteria play a crucial role in human health, for example, by maintaining immune and metabolic homeostasis and protecting against pathogens. Survival in the human intestine depends on the bacterium's ability to utilize complex carbohydrates. Some species are known to use host-derived glycans; for example, Bifidobacteria can utilize O-glycan of mucin.
View Article and Find Full Text PDFProtein trafficking to vacuoles in plants and fungi, and to lysosomes in animals, is essential for the maintenance of cellular homeostasis. In Saccharomyces cerevisiae, the vacuolar protein sorting (VPS) pathway has been well studied by using vacuolar carboxypeptidase Y (CPY) as a model, and many VPS genes have been identified. By contrast, the vacuolar protein trafficking pathway in Schizosaccharomyces pombe remains poorly understood.
View Article and Find Full Text PDFIn filamentous fungi, microtubules are important for polar growth and morphological maintenance and serve as rails for intracellular trafficking. The molecular mechanisms associated with microtubules have been analyzed. However, little is known about when and where tubulin, a component of microtubules, is biosynthesized in multinuclear and multicellular filamentous fungi.
View Article and Find Full Text PDFIn multinuclear and multicellular filamentous fungi little is known about how mRNAs encoding secreted enzymes are transcribed and localized spatiotemporally. To better understand this process we analyzed mRNA encoding GlaA, a glucoamylase secreted in large amounts by the industrial filamentous fungus Aspergillus oryzae, by the MS2 system, in which mRNA can be visualized in living cells. We found that glaA mRNA was significantly transcribed and localized near the hyphal tip and septum, which are the sites of protein secretion, in polarity-dependent expression and localization manners.
View Article and Find Full Text PDFEndo-β-N-acetylglucosaminidases (ENGases) are enzymes that hydrolyze N-linked glycans. Many ENGases have been characterized, but few have been identified with hydrolytic activity towards multi-branched complex-type N-glycans. In this study, three candidate ENGases were identified from Barnesiella intestinihominis based on database searches and phylogenetic analysis.
View Article and Find Full Text PDFN-linked oligosaccharides in the fission yeast Schizosaccharomyces pombe contain large amounts of d-galactose (Gal), which mainly comprises α1,2- and α1,3-linked Gal except for pyruvylated β1,3-linked Gal (PvGalβ) at the non-reducing end. The PvGalβ unit of N-glycans is important for regulating nonsexual flocculation and invasive growth, but the mechanistic basis for β-galactosylation in fission yeast is poorly understood. To gain insight into this mechanism, we have characterized three genes previously identified to be involved in PvGalβ biosynthesis (pvg2, pvg3, and pvg5), with a focus on pvg3, which is predicted to contain a domain conserved in galactosyltransferase family 31 (GT31) proteins.
View Article and Find Full Text PDFTwo natural products, bongkrekic acid and carboxyatractyloside, are known to specifically inhibit the mitochondrial ADP/ATP carrier from its matrix side and cytosolic side, respectively, in concentration ranges of 10 M. In the present study, we investigated the manner of action of a synthetic bongkrekic acid derivative, KH-17, lacking three methyl groups, one methoxy group, and five internal double bonds, on the mitochondrial ADP/ATP carrier. At slightly acidic pH, KH-17 inhibited mitochondrial [ H]ADP uptake, but its inhibitory action was about 10 times weaker than that of its parental compound, bongkrekic acid.
View Article and Find Full Text PDFSchizosaccharomyces japonicus is a dimorphic yeast, transiting between unicellular and hyphal growth. The glycoproteins of fission yeast contain, in addition to mannose (Man), a large number of galactose (Gal) residues. Previously, we reported that the cell-surface O-glycans of S.
View Article and Find Full Text PDFBoth pyruvylation and sialylation onto the terminus of oligosaccharides of N-glycoproteins seem to be structurally and functionally similar with a property of conferring negative charge. However, detailed molecular characteristics of pyruvylation and sialylation in vivo were elusive. Here, to investigate an effect of terminal pyruvylation to N-glycan on in vivo biodistribution and kinetics, we prepared human serum albumin (HSA) modified with pyruvylated N-glycan (PvG), conjugated with HiLyte Fluor 750 (FL750-PvGHSA).
View Article and Find Full Text PDFThe mitotic exit network (MEN) is a conserved signalling pathway essential for the termination of mitosis in the budding yeast . All MEN components are highly conserved in the methylotrophic budding yeast , except for Cdc15 kinase. Instead, we identified two essential kinases OpHcd1 and OpHcd2 () that are homologous to SpSid1 and SpCdc7, respectively, components of the septation initiation network (SIN) of the fission yeast .
View Article and Find Full Text PDFEndo-β-N-acetylglucosaminidases (ENGases) are enzymes that hydrolyze the N-linked oligosaccharides. Many ENGases have already been identified and characterized. However, there are still a few enzymes that have hydrolytic activity toward multibranched complex-type N-glycans on glycoproteins.
View Article and Find Full Text PDFAAA ATPases widely exist in many organisms and function in various organelles. However, there is little information about AAA ATPase functioning in endocytosis. In Aspergillus oryzae, we previously discovered a putative AAA ATPase AipA that would be involved in endocytosis.
View Article and Find Full Text PDFAlthough subcellular localization analysis of proteins fused with enhanced green fluorescence protein (EGFP) has been widely conducted in filamentous fungi, little is known about the localization of messenger RNAs (mRNAs) encoding the EGFP-fused proteins. In this study, we performed single-molecule fluorescence hybridization (smFISH) using an probe to simultaneously visualize EGFP-fused proteins and their mRNAs in the hyphal cells of the filamentous fungus . We investigated the subcellular localization of mRNAs encoding cytoplasmic EGFP, an actin marker protein Lifeact tagged with EGFP, and several EGFP-fused proteins AoSec22, AoSnc1, AoVam3, and AoUapC that localize to the endoplasmic reticulum (ER), the apical vesicle cluster Spitzenkörper, vacuolar membrane, and plasma membrane, respectively.
View Article and Find Full Text PDFBiochim Biophys Acta Biomembr
February 2021
The stm1 (SPAC17C9.10) gene of Schizosaccharomyces pombe is closely related to genes encoding vacuolar PQ-loop proteins, Ypq1, Ypq2, and Ypq3, of Saccharomyces cerevisiae. When stm1 fused with GFP was expressed in fission or budding yeast, Stm1-GFP localized at the vacuolar membrane.
View Article and Find Full Text PDFThe machinery for mRNA localization is one of crucial molecular structures allowing cellular spatiotemporal organization of protein synthesis. Although the molecular mechanisms underlying mRNA localization have been thoroughly investigated in unicellular organisms, little is known about multicellular and multinuclear filamentous fungi. Here, we conducted single-molecule fluorescence hybridization (smFISH) to first visualize the mRNA molecules of α-amylase, which are encoded by , and which are thought to be abundantly secreted from the hyphal tips of the industrially important fungus .
View Article and Find Full Text PDFAlthough β-d-galactofuranosidases (Galf-ases) that hydrolyze β-d-galactofuranose (Galf)-containing oligosaccharides have been characterized in various organisms, to date no Galf-specific Galf-ase-encoding genes have been reported in Aspergillus fungi. Based on the amino acid sequences of previously identified bacterial Galf-ases, here we found two candidate Galf-specific Galf-ase genes AN2395 (gfgA) and AN3200 (gfgB) in the genome of Aspergillus nidulans. Indeed, recombinant GfgA and GfgB proteins exhibited Galf-specific Galf-ase activity, but no detectable α-l-arabinofuranosidase (Araf-ase) activity.
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