Compensatory thio-redox interactions between DsbA, CcdA and CcmG unveil the apocytochrome c holdase role of CcmG during cytochrome c maturation

During cytochrome c maturation (Ccm), the DsbA-dependent thio-oxidative protein-folding pathway is thought to introduce a disulphide bond into the haem-binding motif of apocytochromes c. This disulphide bond is believed to be reduced through a thio-reductive pathway involving the Ccm components CcdA (DsbD), CcmG and CcmH. Here, we show in Rhodobacter capsulatus that in the absence of DsbA cytochrome c levels were decreased and CcdA or CcmG or the putative glutathione transporter CydDC was not needed for Ccm. This decrease was not due to overproduction of the periplasmic protease DegP as a secondary effect of DsbA absence. In contrast, CcmH was absolutely necessary regardless of DsbA, indicating that compensatory thio-redox interactions excluded it. Remarkably, the double (DsbA-CcmG) and triple (DsbA-CcmG-CcdA) mutants produced cytochromes c at lower levels than the DsbA-null mutants, unless they contained a CcmG derivative (CcmG*) lacking its thio-reductive activity. Purified CcmG* can bind apocytochrome c in vitro, revealing for the first time a thiol-independent, direct interaction between apocytochrome c and CcmG. Furthermore, elimination of the thio-redox components does not abolish cytochrome c production, restricting the number of Ccm components essential for haem-apocyt c ligation per se during Ccm.     

A new species of Astragalus (Sect. Proselius) (Leguminosae) from Central Anatolia-Turkey

Astragalus yildirimlii is described and illustrated from Central Anatolia-Turkey. Pollen and seed morphology and chromosome number is given as well. The relationships of the new species are discussed.     

PROGRESS STUDY: Progression of chronic kidney disease in children and heat shock proteins

Various molecular and cellular processes are involved in renal fibrosis, such as oxidative stress, inflammation, endothelial cell injury, and apoptosis. Heat shock proteins (HSPs) are implicated in the progression of chronic kidney disease (CKD). Our aim was to evaluate changes in urine and serum HSP levels over time and their relationships with the clinical parameters of CKD in children. In total, 117 children with CKD and 56 healthy children were examined. The CKD group was followed up prospectively for 24 months. Serum and urine HSP27, HSP40, HSP47, HSP60, HSP70, HSP72, and HSP90 levels and serum anti-HSP60 and anti-HSP70 levels were measured by ELISA at baseline, 12 months, and 24 months. The urine levels of all HSPs and the serum levels of HSP40, HSP47, HSP60, HSP70, anti-HSP60, and anti-HSP70 were higher at baseline in the CKD group than in the control group. Over the months, serum HSP47 and HSP60 levels steadily decreased, whereas HSP90 and anti-HSP60 levels steadily increased. Urine HSP levels were elevated in children with CKD; however, with the exception of HSP90, they decreased over time. In conclusion, our study demonstrates that CKD progression is a complicated process that involves HSPs, but they do not predict CKD progression. The protective role of HSPs against CKD may weaken over time, and HSP90 may have a detrimental effect on the disease course.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12192-021-01239-9.     

<Emphasis Type="Italic">Trichoderma lixii ID11D</Emphasis> seed biopriming mitigates dose dependent salt toxicity in maize

Certain number of commercial products has been developed to grow stress resistant plants for the sustainability of agriculture in current era with full of energy dependency and hunger besides global warming. Given the risk of these products on the microbial environment in the rhizosphere and food security of mankind due to the accumulated chemical pollution through the food web, organic fungal plant growth promoting agents might be used. Hence, effects of Trichoderma lixii ID11D (TXD), our local fungal isolate on Zea mays L. cv. Samada 07 as a seed biopriming agent was investigated under dose dependent NaCl stress in this study. Fungus was characterized based on ITS (internal transcribed spacer) regions via clustering approach after isolated from tea plantation area. The higher the NaCl concentration, the more effective the TXD was observed. Improved electron transport rate (ETR), maximum quantum efficiency of PS II (Fv/Fm), the effective quantum yield of PS2 (ΦPS2), photochemical quenching (qP) and decreased non-photochemical quenching (NPQ) was detected in TXD primed plants after NaCl expose. TXD seed biopriming increased the lengths, fresh and dry weights of root/shoots and decreased the lipid peroxidation (MDA) remarkably. Non-enzymatic pathway was found to be more effective than enzymatic one for seed bioprimed plants proven by higher RWC, soluble protein, proline, chlorophyll, carotenoid, and less H₂O₂ and MDA levels under each dose of NaCl. Detected phenotypic and biochemical improvements pave the way of the potential usage of the formulated fungus biopreperations as a pre-harvest agent in agriculturally important cereals in the future and going beyond lab-based level.     

Lithium-Induced Hypothyroidism: Oxidative Stress and Osmotic Fragility Status in Rats

The present study was conducted to explore the possible effects of different doses of lithium carbonate on thyroid functions, erythrocyte oxidant–antioxidant status, and osmotic fragility. Twenty-four Wistar-type male rats were equally divided into three groups: groups I and II received 0.1 and0.2 % lithium carbonate in their drinking water, respectively, for 30 days. The rats in group III served as controls, drinking tap water without added lithium. At the end of the experimental period, the erythrocyte osmotic fragility and the levels of triiodothyronine (T₃), thyroxine (T₄), thyroid-stimulating hormone (TSH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were measured in blood samples. Compared to controls, there was a statistically significant increase of TSH but decreases of the T₃ and T₄ levels in group II. Both experimental groups showed a statistically significant increase of the maximum osmotic fragility limit. The minimum osmotic fragility values of the animals in group II were statistically higher than those of controls. The standard hemolytic increment curve of both experimental groups was shifted to the right when compared to the curve obtained from the controls. Also, relative to controls, the activities of MDA and SOD were significantly higher and the GSH level lower in group II, but not so in group I. The results of the present study show that treatment with lithium carbonate may result in thyroid function abnormalities, increased oxidative damage, and possible compromise of the erythrocyte membrane integrity resulting from increased osmotic fragility.     

In vitro synthesis of mitochondrial cytochromes P-450(scc) and P-450(11-β) and microsomal cytochrome P-450(C-21) by both free and bound polysomes isolated from bovine adrenal cortex

$\text{In}\text{vitro}$ synthesis of mitochondrial cytochromes P-450(scc) and P-450(11-β), and microsomal cytochrome P-450(C-21) programmed by bovine adrenal cortex polysomes was carried out using rat liver cell sap and wheat germ lysate systems. Synthesis of P-450 proteins in the cell-free systems was determined by immunoprecipitation and immunoadsorption using mono-specific antibodies to each species of P-450, and the sizes of the $\text{in}\text{vitro}$ products were analyzed by SDS-polyacrylamide gel electrophoresis. Both free and bound polysomes synthesized these three species of P-450 in the cell-free systems. P-450(scc) and P-450(C-21) were synthesized apparently as the mature size products, whereas P-450(11-β) was synthesized as a putative precursor approximately 5,000 daltons larger than the mature form. Mitochondrial and microsomal P-450 proteins seem to share common sites of synthesis in the cytoplasm of adrenal cortex cells.     

Mutations in the gene encoding the Wnt-signaling component R-spondin 4 (RSPO4) cause autosomal recessive anonychia

Anonychia is an autosomal recessive disorder characterized by the congenital absence of finger- and toenails. In a large German nonconsanguineous family with four affected and five unaffected siblings with isolated total congenital anonychia, we performed genomewide mapping and showed linkage to 20p13. Analysis of the RSPO4 gene within this interval revealed a frameshift and a nonconservative missense mutation in exon 2 affecting the highly conserved first furin-like cysteine-rich domain. Both mutations were not present among controls and were shown to segregate with the disease phenotype. RSPO4 is a member of the recently described R-spondin family of secreted proteins that play a major role in activating the Wnt/ beta -catenin signaling pathway. Wnt signaling is evolutionarily conserved and plays a pivotal role in embryonic development, growth regulation of multiple tissues, and cancer development. Our findings add to the increasing body of evidence indicating that mesenchymal-epithelial interactions are crucial in nail development and put anonychia on the growing list of congenital malformation syndromes caused by Wnt-signaling-pathway defects. To the best of our knowledge, this is the first gene known to be responsible for an isolated, nonsyndromic nail disorder.     

Role of the nitric oxide pathway in ischemia-reperfusion injury in isolated perfused guinea pig lungs

We examined the role of the nitric oxide (NO) pathway on ischemia-reperfusion injury via the use of isolated perfused guinea pig lungs. We administered both L-Arginine and N-nitro-L-arginine methyl ester (L-NAME) to the lungs in or after 3 h of ischemia. We observed pulmonary artery pressures as well as tissue and perfusate malondialdehyde (MDA) and glutathione (GSH) levels. We observed that L-NAME significantly increased both tissue and perfusate GSH levels and pulmonary artery pressures, but it decreased both tissue and perfusate MDA levels. On the other hand, L-arginine significantly decreased pulmonary artery pressure and both tissue and perfusate glutathione levels, but it increased both tissue and perfusate MDA levels. Electron microscopic evaluation supported our findings by indicating the preservation of lamellar bodies of type II pneumocytes. We concluded that L-NAME administration during reperfusion improves lung recovery from ischemic injury.