Two cDNA clones coding for the legumin protein of Pisum sativum L. contain sequence repeats

The sequence of two cDNA clones coding for the whole of the -subunit and most of the -subunit of legumin are presented together with a considerable amount of protein sequence data to confirm the predicted amino acid sequence. A unique feature shown by these cDNAs is the presence of three 56 base pair tandem repeats in the region encoding the C terminal of the polypeptide. The tandem repeats are also exhibited in the predicted polypeptide sequence as three 18 amino acid repeats which contain extremely high proportions of polar, mainly acidic, residues. The new sequences are compared to the previously published sequence of some shorter legumin cDNAs (Nature 295: 76–79). In the region where the sequences overlap, the previous cDNAs differ from the new ones by only a few base substitutions but most of the repeated region is not present though the sequences on either side are. The possibility that the absence of the repeats may reflect the difference between two types of legumin gene, rather than an artefact of the cloning of the cDNAs, is discussed.     

The CXCR1 tail mediates beta1 integrin-dependent cell migration via MAP kinase signaling

In this study, we examined how IL-8 induces leukocyte migration on major beta1 integrin ligands derived from the extracellular matrix protein fibronectin. We assessed individual contributions of signaling by IL-8 receptors by transfection of CXCR1 and CXCR2 into rat basophilic leukemia (RBL) cells and human monocytic THP-1 cells. CXCR1 expressing cells migrated on the fibronectin ligands for alpha4beta1 and alpha5beta1 integrins in response to IL-8, whereas CXCR2 expressing cells did not. RBL cells expressing the chimeric CXCR1 receptor containing the cytoplasmic tail of CXCR2 had greatly blunted migration, while cells expressing the CXCR2 chimera with the tail of CXCR1 had augmented migration. Last, inhibitors of p38 and JNK MAP kinases blocked IL-8-induced migration in CXCR1+ cells. We conclude that IL-8 stimulated beta1 integrin-mediated leukocyte migration on fibronectin through CXCR1 is dependent on the C-terminal cytoplasmic domain of CXCR1 and subsequent p38 and JNK MAPK signaling.     

Identification of novel pyrrolopyrazoles as protein kinase C β II inhibitors

A novel series of pyrrolopyrazole-based protein kinase C β II inhibitors has been identified from high-throughput screening. Herein, we report our initial structure-activity relationship studies with a focus on optimizing compound ligand efficiency and physicochemical properties, which has led to potent inhibitors with good cell permeability.     

Removal of persistent organic pollutants from micro-polluted drinking water by triolein embedded absorbent

A new biomimetic absorbent, cellulose acetate (CA) embedded with triolein (CA-triolein), was prepared and applied for the removal of persistent organic pollutants (POPs) from micro-polluted aqueous solution. The comparison of CA-triolein, CA and granular activated carbon (GAC) for dieldrin removal was investigated. Results showed that CA-triolein absorbent gave a lowest residual concentration after 24 h although GAC had high removal rate in the first 4 h adsorption. Then the removal efficiency of mixed POPs (e.g. aldrin, dieldrin, endrin and heptachlor epoxide), absorption isotherm, absorbent regeneration and initial column experiments of CA-triolein were studied in detail. The linear absorption isotherm and the independent absorption in binary isotherm indicated that the selected POPs are mainly absorbed onto CA-triolein absorbent by a partition mechanism. The absorption constant, K, was closely related to the hydrophobic property of the compound. Thermodynamic calculations showed that the absorption was spontaneous, with a high affinity and the absorption was an endothermic reaction. Rinsing with hexane the CA-triolein absorbent can be regenerated after absorption of POPs. No significant decrease in the dieldrin removal efficiency was observed even when the absorption–regeneration process was repeated for five times. The results of initial column experiments showed that the CA-triolein absorbent did not reach the breakthrough point at a breakthrough empty-bed volume (BV) of 3200 when the influent concentration was 1–1.5 μg/L and the empty-bed contact time (EBCT) was 20 min.     

Effect of lanthanum on ion absorption in cucumber seedling leaves

Scanning electron microscope and energy-dispersive X-ray analysis were used to study the tissular distributions of elements Na, Mg, Cl, K, Ca, Mn, and Fe in leaves of cucumber seedlings in the absence or presence of La³⁺. The results showed that the atomic percentages of Na, Mg, Cl, K, and Ca were basically reduced and those of Mn and Fe were increased in the presence of La³⁺; in addition, at 0.02 mM La³⁺, the reduced or increased degrees were higher than those at 2.0 mM La³⁺. The effects of La³⁺ on ion absorption were similar to those of Ca²⁺, suggesting that the rare earth element lanthanum affects the plant physiological mechanism by regulating the Ca²⁺ level in plant cell.     

Moderate heat stress of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> leaves causes chloroplast swelling and plastoglobule formation

Photosynthesis is inhibited by heat stress. This inhibition is rapidly reversible when heat stress is moderate but irreversible at higher temperature. Absorbance changes can be used to detect a variety of biophysical parameters in intact leaves. We found that moderate heat stress caused a large reduction of the apparent absorbance of green light in light-adapted, intact Arabidopsis thaliana leaves. Three mechanisms that can affect green light absorbance of leaves, namely, zeaxanthin accumulation (absorbance peak at 505 nm), the electrochromic shift (ECS) of carotenoid absorption spectra (peak at 518 nm), and light scattering (peak at 535 nm) were investigated. The change of green light absorbance caused by heat treatment was not caused by changes of zeaxanthin content nor by the ECS. The formation of non-photochemical quenching (NPQ), chloroplast movements, and chloroplast swelling and shrinkage can all affect light scattering inside leaves. The formation of NPQ under high temperature was not well correlated with the heat-induced absorbance change, and light microscopy revealed no appreciable changes of chloroplast location because of heat treatment. Transmission electron microscopy results showed swollen chloroplasts and increased number of plastoglobules in heat-treated leaves, indicating that the structural changes of chloroplasts and thylakoids are significant results of moderate heat stress and may explain the reduced apparent absorbance of green light under moderately high temperature.     

Exogoninae (Polychaeta: Syllidae) from the Mexican Caribbean region with a key for the Gran Caribbean species]

This paper identifies the Exogoninae (Syllidae) from the Mexican Caribbean coasts and includes a key to identify all the species recorded from the Grand Caribbean Sea. The classification of the family and the composition of Exogoninae are briefly examined; the correct names of the subfamilies are Syllinae Grube, 1850, Eusyllinae Malaquin, 1893, Autolytinae Malaquin, 1893 and Exogoninae Langerhans, 1879. Exogoninae includes Anguillosyllis Day, 1963, Brania de Quatrefages, 1866, Braniella Hartman, 1963, Exogone ?rsted, 1845, Exogonella Hartman, 1961, Exogonoides Day, 1963, Parapionosyllis Fauvel, 1923, Psammosyllis Westheide, 1990, Spermosyllis Claparède, 1864, and Sphaerosyllis Claparède, 1863. Pseudexogone Augener, 1922, formerly included in the group, is not a syllid; it belongs to Pilargidae. We collected 814 specimens belonging to 3 genera, 3 subgenera and 13 species as Brania (4), Exogone (4) and Sphaerosyllis (5); five new species are described: Brania russelli n. sp, Brania uebelackerae n. sp, Brania westheidei n. sp., Exogone (Exogone) bondi n. sp. and Exogone (Parexogone) sanmartini n. sp. For each species, selected references, diagnostic features, observations on morphological variability, distribution and illustrations are provided; new species also have an english diagnosis. Most abundant species were B. uebelackerae n. sp. (295), S. taylori Perkins (169), E. (E.) dispar Webster (76), and E. (E.) bondi n sp. (72).