Comparative Allelopathic Effects of Two Weed Extracts on Seed Germination and Seedling Growth of Vigna unguiculata (L.) Walp. and Abelmoschus esculentus L.

Pot culture experiment and Petri dish bioassay were conducted to assess the allelopathic potential of Cyanthillium cinereum and Lantana camara on seed germination and seedling growth of Vigna unguiculata and Abelmoschus esculentus. Aqueous leaf and stem extracts of weed were used for treatment. The differential inhibitory effect was observed for two weed plants on two tested crops. The experimental results revealed that in case of pot culture experiment, lowest germination percentages (40.8±0.49%, 63.6±0.60% and 83±0.78%) were recorded in L. camara leaf extract treated set of A. esculentus and maximum decrease in seedling length (0.31±0.05 cm, 4.18±0.07 cm, 6.42±0.08 cm and 13.51±0.07 cm) was observed in stem extract treated a set of A. esculentus. L. camara stem and leaf extract induced a more negative effect on seedling length in both A. esculentus and V. unguiculata. For petridish bioassay experiment, lowest germination percentages (54.60±0.40%, 59.20±0.49%, 66.20±0.74% and 69.80±0.38%) were observed in L. camara leaf extract treated a set of A. esculentus. In V. unguiculata, lowest germination percentage (45.8±0.49%, 75.4±0. 40%, 84.4±0.25% and 89±0.32%) was observed in stem extract treated set. Maximum suppressive effect on seedling length was recorded for stem and leaf extract of C. cinereum of A. esculentus and leaf extract of L. camara and stem extract of C. cinereum of V. unguiculata

Implications on zinc binding to S100A2

AbstractHuman S100A2 is an EF-hand calcium-binding S100 protein that is localized mainly in the nucleus and functions as tumor suppressor. In addition to Ca2+ S100A2 binds Zn2+ with a high affinity. Studies have been carried out to investigate whether Zn2+ acts as a regulatory ion for S100A2, as in the case of Ca2+. Using the method of competition with the Zn2+ chelator 4-(2-pyridylazo)-resorcinol, an apparent Kd of 25 nM has been determined for Zn2+ binding to S100A2. The affinity lies close to the range of intracellular free Zn2+ concentrations, suggesting that S100A2 is able to bind Zn2+ in the nucleus. Two Zn2+-binding sites have been identified using site directed mutagenesis and several spectroscopic techniques with Cd2+ and Co2+ as probes. In site 1 Zn2+ is bound by Cys21 and most likely by His 17. The binding of Zn2+ in site 2 induces the formation of a tetramer, whereby the Zn2+ is coordinated by Cys2 from each subunit. Remarkably, only binding of Zn2+ to site 2 substantially weakens the affinity of S100A2 for Ca2+. Analysis of the individual Ca2+-binding constants revealed that the Ca2+ affinity of one EF-hand is decreased about 3-fold, whereas the other EF-hand exhibits a 300-fold decrease in affinity. These findings imply that S100A2 is regulated by both Zn2+ and Ca2+, and suggest that Zn2+ might deactivate S100A2 by inhibiting response to intracellular Ca2+ signals

Asterix/Gtsf1 links tRNAs and piRNA silencing of retrotransposons.

The Piwi-interacting RNA (piRNA) pathway safeguards genomic integrity by silencing transposable elements (transposons) in the germline. While Piwi is the central piRNA factor, others including Asterix/Gtsf1 have also been demonstrated to be critical for effective silencing. Here, using enhanced crosslinking and immunoprecipitation (eCLIP) with a custom informatic pipeline, we show that Asterix/Gtsf1 specifically binds tRNAs in cellular contexts. We determined the structure of mouse Gtsf1 by NMR spectroscopy and identified the RNA-binding interface on the protein's first zinc finger, which was corroborated by biochemical analysis as well as cryo-EM structures of Gtsf1 in complex with co-purifying tRNA. Consistent with the known dependence of long terminal repeat (LTR) retrotransposons on tRNA primers, we demonstrate that LTR retrotransposons are, in fact, preferentially de-repressed in Asterix mutants. Together, these findings link Asterix/Gtsf1, tRNAs, and LTR retrotransposon silencing and suggest that Asterix exploits tRNA dependence to identify transposon transcripts and promote piRNA silencing

Assigning Backbone NMR Resonances for Full Length Tau Isoforms: Efficient Compromise between Manual Assignments and Reduced Dimensionality

Tau protein is the longest disordered protein for which nearly complete backbone NMR resonance assignments have been reported. Full-length tau protein was initially assigned using a laborious combination of bootstrapping assignments from shorter tau fragments and conventional triple resonance NMR experiments. Subsequently it was reported that assignments of comparable quality could be obtained in a fully automated fashion from data obtained using reduced dimensionality NMR (RDNMR) experiments employing a large number of indirect dimensions. Although the latter strategy offers many advantages, it presents some difficulties if manual intervention, confirmation, or correction of the assignments is desirable, as may often be the case for long disordered and degenerate polypeptide sequences. Here we demonstrate that nearly complete backbone resonance assignments for full-length tau isoforms can be obtained without resorting either to bootstrapping from smaller fragments or to very high dimensionality experiments and automation. Instead, a set of RDNMR triple resonance experiments of modest dimensionality lend themselves readily to efficient and unambiguous manual assignments. An analysis of the backbone chemical shifts obtained in this fashion indicates several regions in full length tau with a notable propensity for helical or strand-like structure that are in good agreement with previous observations

Dermato-Radiological Evaluation of Congenital Limb Overgrowth Vascular Syndromes

International Society for the Study of Vascular Anomalies classification defines Congenital Limb Overgrowth Vascular Syndromes (CLOS) as a subset of vascular syndromes with other abnormalities that present with unilateral limb overgrowth. It includes Klippel–Trenaunay Syndrome, Parkes–Weber Syndrome, CLOVES (Congenital Lipomatous Overgrowth, Vascular Malformations, Epidermal Nevi, Spinal/Skeletal Anomalies/Scoliosis) Syndrome, Proteus Syndrome, PTEN Hamartomatous Syndrome, and Fibroadipose Vascular Anomaly. Due to their rare and complex nature, a multidisciplinary approach to diagnosis and treatment is required. A thorough clinical and radiological workup can go miles in reflecting on the patient’s outcome. Here we report five cases of CLOS with their detailed dermato-radiological profiles

¹⁵N/¹H HSQC spectrum for free state tau352 with peak assignments given by residue numbers for the longest tau isoforms (tau441).

<p>The highly overlapped region (box) is enlarged.</p

¹³C/¹H strip plots from 3D (left) and (4,3)D (right; additive experiment) HNCACB experiments, at ¹⁵N chemical shifts of 125.69 ppm and 125.67 ppm, respectively, for Tau K19 K257T.

<p>Shown are the spin systems for residues Gln307 and Glu338 (corresponding to tau352 residues 218 and 249) which can be better and more accurately resolved and identified using the GFT linear combinations. Positive peaks are shown in black and negative peaks are in red.</p