Characteristics and phylogenetic analysis of the complete mitochondrial genome of <i>Glyptothorax pallozonus</i> (Siluriformes, Sisoridae)

Glyptothorax pallozonus Lin, 1934 is a small benthic fish belonging to the Sisoridae family that is distributed in the Dongjiang and Rongjiang Rivers of China. In the present study, we sequenced and characterized the complete mitochondrial genome of G. pallozonus for the first time. The complete mitogenome of G. pallozonus is 16,542 bp in length and includes 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNA (rRNAs), and a control region (CR). The mitogenome architecture was identical to that of other teleosts. Maximum likelihood (ML) phylogenetic analysis strongly supported the monophyly of Glyptothorax, which contains two clades. These results advance our understanding of the molecular phylogeny of the genus Glyptothorax.</p

Heterologous Expression and Characterization of a Novel Chitinase (ChiEn1) from <i>Coprinopsis cinerea</i> and its Synergism in the Degradation of Chitin

Chitinase ChiEn1 did not hydrolyze insoluble chitin but showed hydrolysis and transglycosylation activities toward chitin-oligosaccharides. Interestingly, the addition of ChiEn1 increased the amount of reducing sugars released from chitin powder by endochitinase ChiIII by 105.0%, and among the released reducing sugars the amount of (GlcNAc)₂ was increased by 149.5%, whereas the amount of GlcNAc was decreased by 10.3%. The percentage of GlcNAc in the products of chitin powder with the combined ChiIII and ChiEn1 was close to that in the products of chitin-oligosaccharides with ChiEn1, rather than that with ChiIII. These results indicate that chitin polymers are first degraded into chitin oligosaccharides by ChiIII and the latter are further degraded to monomers and dimers by ChiEn1, and the synergistic action of ChiEn1 and ChiIII is involved in the efficient degradation of chitin in cell walls during pileus autolysis. The structure modeling explores the molecular base of ChiEn1 action

Improved Polysaccharide Production by Homologous Co-overexpression of Phosphoglucomutase and UDP Glucose Pyrophosphorylase Genes in the Mushroom <i>Coprinopsis cinerea</i>

Coprinopsis polysaccharides exhibit hypoglycemic and antioxidant activities. In this report, increases in polysaccharide production by homologous co-overexpression or individual homologous overexpression of phosphoglucomutase and UDP glucose pyrophosphorylase gene in <i>Coprinopsis cinerea</i>, which participate in polysaccharide biosynthesis. The transcription levels of the target genes were upregulated significantly in the oePGM-UGP strain when compared with the oePGM or oeUGP strain. The maximum intracellular polysaccharide content obtained in the oePGM-UGP strain was 1.49-fold higher than that of the WT strain, whereas a slight improvement in polysaccharide production was obtained in the oePGM and oeUGP strains. Extracellular polysaccharide production was enhanced by 75% in the oePGM-UGP strain when compared with that of the WT strain, whereas improvements of 30% and 16% were observed for the oePGM and oeUGP strains, respectively. These results show that multiple interventions in polysaccharide biosynthesis pathways of Basidiomycetes might improve polysaccharide yields when compared with that of single interventions

The Modes of Action of ChiIII, a Chitinase from Mushroom Coprinopsis cinerea, Shift with Changes in the Length of GlcNAc Oligomers

A putative class III endochitinase (ChiIII) was reported previously to be expressed dominantly in fruiting bodies of Coprinopsis cinerea, and its expression levels increased with the maturation of the fruiting bodies. This paper further reports that ChiIII is a novel chitinase with exo- and endoactivities. When the substrate was (GlcNAc)_3–5, ChiIII exhibited exoactivity, releasing GlcNAc processively from the reducing end of (GlcNAc)_3–5; when the substrate was (GlcNAc)_6–7, the activity of ChiIII shifted to an endoacting enzyme, randomly splitting chitin oligosaccharides to various shorter oligosaccharides. This shift in the mode of action of ChiIII may be related to its stronger hydrolytic capacity to degrade chitin in fungal cell walls. The predicted structure of ChiIII shows that it lacks the α+β domain insertion; however, its substrate binding cleft seems to be deeper than that of common endochitinases but shallower and more open than that of common exochitinases, which may be related to its exo- and endohydrolytic activities

Effective Adsorption Separation of <i>n</i>‑Hexane/2-Methylpentane in Facilely Synthesized Zeolitic Imidazolate Frameworks ZIF‑8 and ZIF-69

A facile synthesis procedure was built to synthesize zeolitic imidazolate frameworks (ZIFs) ZIF-8 and ZIF-69 under ambient conditions with the prevention of organic solvents. ZIF-69 adsorbent was first introduced in the liquid-phase separation of hexane isomers. A sieving test was carried out using samples of <i>n</i>-hexane (<i>n</i>HEX) or 2-methylpentane (2MP) over two ZIFs and commercial 5A zeolite materials. According to batch adsorption performances and modeling, ZIF-8 exhibits the highest adsorption selectivity and capacity for <i>n</i>HEX, followed by ZIF-69 and 5A zeolite. The equilibrium data at 25 °C show that a significant amount (0.51 g/g) of <i>n</i>HEX and only 0.09 g/g 2MP can be adsorbed in ZIF-8. And the maximum adsorption capacity of <i>n</i>HEX and 2MP on ZIF-69 are 0.34 g/g and 0.10 g/g, respectively. Breakthrough experiments performed at 150 °C with a binary mixture of <i>n</i>HEX/2MP confirm the shape selectivity and adsorption capacities of ZIF-8 toward <i>n</i>HEX at various total pressures from 0.5 to 1.3 MPa and with different feed concentrations, which is attributed to the flexible architecture of ZIF-8 and its excellent shape match with <i>n</i>HEX

Comparative Study of Nonautolytic Mutant and Wild-Type Strains of <i>Coprinopsis cinerea</i> Supports an Important Role of Glucanases in Fruiting Body Autolysis

Autolysis of <i>Coprinopsis cinerea</i> fruiting bodies affects its commercial value. In this study, a mutant of <i>C. cinerea</i> that exhibits pileus expansion without pileus autolysis was obtained using ultraviolet mutagenesis. This suggests that pileus expansion and pileus autolysis involve different enzymes or proteins. Among the detected hydrolytic enzymes, only β-1,3-glucanase activity increased with expansion and autolysis of pilei in the wild-type strain, but the increase was abolished in the mutant. This suggests that β-1,3-glucanases plays a major role in the autolysis. Although there are 43 possible β-1,3-glucoside hydrolases genes, only 4 known genes, which have products that are thought to act synergistically to degrade the β-1,3-glucan backbone of cell walls during fruiting body autolysis, and an unreported gene were upregulated during pileus expansion and autolysis in the wild-type stain but were suppressed in the mutant. This suggests that expression of these β-1,3-glucanases is potentially controlled by a single regulatory mechanism

Clustal alignment and nuclear localization signal sequence analysis of Rpl32 paralogs.

<p>(A) Clustal alignment between Rrpl32-1 and Rpl32-2. Identical residues shared by these two paralogs are shaded black. (B) Localization of DAPI fluoresence (left), EGFP fluoresence (middled) and merged fluoresece (right) in <i>rpl32-1-egfp</i>,<i>rpl32-2-egfp</i>, <i>rpl32-1-23-egfp</i> or <i>rpl32-2-23-egfp</i> cells in log phase. Scale bar: 10 µm.</p

Expression of Rpl32 paralogs varied with different nutrient conditions during cultivation.

<p>(A) The growth curve of WT cells (upper panel), and changes of mRNA level (upper panel) and protein level (lower panel) of Rpl32 paralogs in WT cells during cultivation. (B) mRNA level (upper panel) and protein level (lower panel) of Rpl32 paralogs in WT cells cultured in fresh EMM2, cell-free SP EMM2, cell-free LP EMM2, EMM2-N or EMM2-C medium respectively. QPCR was used for analysis of transcription level standardized with <i>ACT1</i>. Western blot was used for analysis of protein level and β-actin was an internal control.</p

Paralogous Ribosomal Protein L32-1 and L32-2 in Fission Yeast May Function Distinctively in Cellular Proliferation and Quiescence by Changing the Ratio of Rpl32 Paralogs

<div><p>Fission yeast cells express Rpl32-2 highly while Rpl32-1 lowly in log phase; in contrast, expression of Rpl32-1 raises and reaches a peak level while Rpl32-2 is downregulated to a low basic level when cells enter into stationary phase. Overexpression of Rpl32-1 inhibits cell growth while overexpression of Rpl32-2 does not. Deleting <i>rpl32-2</i> impairs cell growth more severely than deleting <i>rpl32-1</i> does. Cell growth impaired by deleting either paralog can be rescued completely by reintroducing <i>rpl32-2</i>, but only partly by <i>rpl32-1.</i> Overexpression of Rpl32-1 inhibits cell division, yielding 4c DNA and multiple septa, while overexpressed Rpl32-2 promotes it. Transcriptomics analysis proved that Rpl32 paralogs regulate expression of a subset of genes related with cell division and stress response in a distinctive way. This functional difference of the two paralogs is due to their difference of 95^th amino acid residue. The significance of a competitive inhibition between Rpl32 paralogs on their expression is discussed.</p> </div

Transcriptomic patterns of WT, <i>rpl32-1</i> or <i>rpl32-2</i> cells respectively in log or stationary phase.

<p>Color panel indicates relative increase (red), decrease (blue) and median (white) of transcription level for 64 genes regulated by Rpl32-1 and Rpl32-2 in a distinctive way (at least 2-fold changes). Bold type means genes are regulated oppositely by both Rpl32 paralogs (Fold change >2) and nonbold type means genes are regulated by either of Rpl32 paralogs (Fold change >2). * Changes in transcripts level were confirmed by QPCR.</p