Structures of novel sialylated O-linked oligosaccharides isolated from human erythrocyte glycophorins

The O-linked oligosaccharides attached to human erythrocyte glycophorins were extensively characterized. In addition to the previously described disialylated tetrasaccharide, NeuNAc alpha 2----3Gal beta 1----3 (Neu-NAc alpha 2----6)GalNAcOH and monosialylated trisaccharide, NeuNAc alpha 2----3Gal beta 1----3GalNAcOH, novel trisialylated oligosaccharides were isolated. Methylation analysis, fast atom bombardment-mass spectrometry, and enzymatic degradation were used to elucidate the following novel structures: formula; see text: These results suggest that O-linked oligosaccharides with a disialosyl group, NeuNAc alpha 2----8NeuNAc alpha 2----, may be present in various tissues.     

Purification and Some Properties of Nucleases from Shii-take,Lentinus edodes

Three kinds of nuclease preparations, each of which having both endonuclease activity that formed 5′-mononucleotides and 3′-nucleotidase activity, were separated and partially purified from Shii-take, Lentinus edodes. Both enzyme activities of each preparation showed a similar thermostability and electrophoretic mobility on Polyacrylamide gel, and a competitive relationship was observed between RNA and 3′-AMP in their enzyme reactions. From these results, it is concluded that both enzyme activities of these three preparations reside in a single protein, respectively. They resemble one another in substrate specificity, cleavage pattern of RNA and thermostability, but are distinguishable from one another by molecular weight, electrophoretic mobility and optimum pH for degradation of RNA.     

ADAMTSL6β promotes fibrillin‐1 microfibril assembly,which is possibly mediated via binding through the third thrombospondin type I domain to fibrillin‐1

Fibrillin‐1 is the major component of extracellular matrix microfibrils. Microfibrils dysfunction is responsible for the onset of various connective tissue diseases, including Marfan syndrome. Although ADAMTSL (a disintegrin and metalloproteinase with thrombospondin motifs‐like) 6β is one of the fibrillin‐1 binding proteins, the detailed mechanism underlying the involvement of ADAMTSL6β in microfibril formation remains unclear. In this study, we created deletion mutants of ADAMTSL6β and examined their interactions with fibrillin‐1 assembly. Pull‐down assay of the ADAMTSL6β deletion mutants and fibrillin‐1 protein revealed that ADAMTSL6β binds to fibrillin‐1 through the third thrombospondin type I domain. Furthermore, we observed that formation of fibrillin‐1 matrix assembly was enhanced in MG63 cells, expressing full‐length ADAMTSL6β, when compared with that of wild type MG63 cells. While MG63 cells expressing Δ TSP3‐ADAMTSL6β form showed enhanced assembly formation, Δ TSP2‐ADAMTSL6β form did not enhance that, indicating the difference between Δ TSP2‐Δ TSP3 has a critical role for fibrillin‐1 assembly. As the difference of Δ TSP2‐Δ TSP3 is the third thrombospondin type I domain, we concluded that the third thrombospondin type I domain of ADAMTSL6β influence the microfibril formation. Our data are the functional presentation of the biological role of ADAMTSL6β in the process of microfibril formation.     

Fundamental mechanisms of the stem cell regulation in land plants: lesson from shoot apical cells in bryophytes

Plant Molecular Biology - This review compares the molecular mechanisms of stem cell control in the shoot apical meristems of mosses and angiosperms and reveals the conserved features and evolution...     

Plant stem cell research is uncovering the secrets of longevity and persistent growth

Plant stem cells have several extraordinary features: they are generated de novo during development and regeneration, maintain their pluripotency, and produce another stem cell niche in an orderly manner. This enables plants to survive for an extended period and to continuously make new organs, representing a clear difference in their developmental program from animals. To uncover regulatory principles governing plant stem cell characteristics, our research project ‘Principles of pluripotent stem cells underlying plant vitality’ was launched in 2017, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Japanese government. Through a collaboration involving 28 research groups, we aim to identify key factors that trigger epigenetic reprogramming and global changes in gene networks, and thereby contribute to stem cell generation. Pluripotent stem cells in the shoot apical meristem are controlled by cytokinin and auxin, which also play a crucial role in terminating stem cell activity in the floral meristem; therefore, we are focusing on biosynthesis, metabolism, transport, perception, and signaling of these hormones. Besides, we are uncovering the mechanisms of asymmetric cell division and of stem cell death and replenishment under DNA stress, which will illuminate plant-specific features in preserving stemness. Our technology support groups expand single-cell omics to describe stem cell behavior in a spatiotemporal context, and provide correlative light and electron microscopic technology to enable live imaging of cell and subcellular dynamics at high spatiotemporal resolution. In this perspective, we discuss future directions of our ongoing projects and related research fields.     

Factors determining vegetation recovery after abandonment of coal-mining villages

Landscape and Ecological Engineering - There have been many earlier studies of the biodiversity and ecosystem services of abandoned farmlands, but studies of abandoned villages are limited,...     

Factors influencing lifespan dependency on agricultural crops by brown bears

Landscape and Ecological Engineering - Investigating factors underlying human-wildlife conflicts in agricultural landscapes is important for both preventing crop damage and wildlife conservation....     

Oxysterols As Indices of Oxidative Stress in Man After Paraquat Ingestion

The aim of this study is to evaluate oxidative stress in man after paraquat ingestion by analyzing 7 &#102 - and 7 &#103 -hydroperoxycholest-5-en-3 &#103 -ol (7 &#102 - and 7 &#103 -OOH) as well as oxysterols, cholesterol oxidation products, as indices of lipid peroxidation. Lung, kidney, and liver were collected at autopsy from seven patients with paraquat poisoning and seven controls matched for age and sex. We identified for the first time 7-ketocholesterol (7-keto) and 7-hydroxycholesterol (7 &#102 -OH and 7 &#103 -OH) in human kidney by LC-MS. Next, we quantified 7 &#102 -OOH and 7 &#103 -OOH by HPLC with postcolumn chemiluminescence as well as oxysterols by HPLC-UV. Both 7 &#102 -OOH and 7 &#103 -OOH detected in lung and kidney from the controls were as low as the paraquat group. In contrast, we found both 7-keto and 7 &#103 -OH in lung and 7-keto in kidney from the paraquat group were significantly higher than from the controls. This is the first report on accumulated oxysterols in lung and kidney from human paraquat poisoning. It seems to reflect greater oxidative stress in the pathology of paraquat intoxication.     

Synthesis of 1,1,2-trisubstituted cyclopropane nucleosides in enantiomerically pure forms

Abstract

Due to the unique rigid and small steric feature of cyclopropane, cyclopropane nucleosides (CPNs) in which the ribose (deoxyribose) of nucleosides are replaced by a hydroxy-substituted cyclopropane, are of great biological interest. Novel 1,1,2-trisubstituted cyclopropane nucleosides were synthesized in enantiomerically pure forms as potential antiviral agents. In the synthesis, two cyclopropane tosylates, which were prepared from chiral cyclopropane lactones previously reported by us, were used effectively as common intermediates for the CPNs. These CPNs are also potentially useful as nucleoside units to incorporate into oligonucleotides in nucleic acids chemotherapy studies.