Enzymatic activity of the Arabidopsis sulfurtransferase resides in the C-terminal domain but is boosted by the N-terminal domain and the linker peptide in the full-length enzyme

Sulfurtransferases/rhodaneses are a group of enzymes widely distributed in plants, animals, and bacteria that catalyze the transfer of sulfur from a donor molecule to a thiophilic acceptor substrate. Sulfurtransferases (STs) consist of two globular domains of nearly identical size and conformation connected by a short linker sequence. In plant STs this linker sequence is exceptionally longer than in sequences from other species. The Arabidopsis ST1 protein (AJ131404) contains five cysteine residues: one residue is universally conserved in all STs and considered to be catalytically essential; a second one, closely located in the primary sequence, is conserved only in sequences from eukaryotic species. Of the remaining three cysteine residues two are conserved in the so far known plant STs and one is unique to the Arabidopsis ST1. The aim of our study was to investigate the role of the twodomain structure, of the unique plant linker sequence and of each cysteine residue. The N and C-terminal domains of the Arabidopsis ST1, the fulllength protein with a shortened linker sequence and several pointmutated proteins were overexpressed in E. coli, purified and used for enzyme activity measurements. The C-terminal domain itself displayed ST activity which could be increased by adding the separately prepared N-terminal domain. The activity of an ST1 derivative with a shortened linker sequence was reduced by more than 60% of the wild-type activity, probably because of a drastically reduced protein stability. The replacement of each cysteine residue resulted in mutant forms which differed significantly in their stability, in the specific ST activities, and in their kinetic parameters which were determined for 3-mercaptopyruvate as well as thiosulfate as sulfur substrates: mutation of the putative active site cysteine (C332) essentially abolished activity; for C339 a crucial role at least for the turnover of thiosulfate could be identified.DFG/PA/764/1-1DFG/PA/764/1-2Fonds der Chemischen Industri

The Deep Space Network: A Radio Communications Instrument for Deep Space Exploration

The primary purpose of the Deep Space Network (DSN) is to serve as a communications instrument for deep space exploration, providing communications between the spacecraft and the ground facilities. The uplink communications channel provides instructions or commands to the spacecraft. The downlink communications channel provides command verification and spacecraft engineering and science instrument payload data

PeanutMap: an online genome database for comparative molecular maps of peanut

BACKGROUND: Molecular maps have been developed for many species, and are of particular importance for varietal development and comparative genomics. However, despite the existence of multiple sets of linkage maps, databases of these data are lacking for many species, including peanut. DESCRIPTION: PeanutMap provides a web-based interface for viewing specific linkage groups of a map set. PeanutMap can display and compare multiple maps of a set based upon marker or trait correspondences, which is particularly important as cultivated peanut is a disomic tetraploid. The database can also compare linkage groups among multiple map sets, allowing identification of corresponding linkage groups from results of different research projects. Data from the two published peanut genome map sets, and also from three maps sets of phenotypic traits are present in the database. Data from PeanutMap have been incorporated into the Legume Information System website to allow peanut map data to be used for cross-species comparisons. CONCLUSION: The utility of the database is expected to increase as several SSR-based maps are being developed currently, and expanded efforts for comparative mapping of legumes are underway. Optimal use of these data will benefit from the development of tools to facilitate comparative analysis

Effects of stator and rotor core ovality on induction machine behavior

Asymmetries in the air gap of induction motors produce additional harmonics in the flux density and force waves. A complete transient finite element model analyzes the harmonics produced from two possible asymmetries, a stator core ovality and a rotor ovality. The analysis of the air gap flux density and magnetic force waves determined by the finite element model shows unique harmonic frequencies due to the ovality of the air gap

Genetic enhancement of Valencia core collection and molecular characterization of U.S. peanut mini core collection using SSR markers

A core collection is a gateway for the utilization of diverse accessions with beneficial traits in applied breeding programs. 630 USDA Valencia peanut germplasm and a control cultivar (New Mexico Valencia C) were evaluated for 26 descriptors in augmented design for two seasons. The accessions were stratified by country of origin, and data on morphological and agronomic descriptors were used for clustering following Ward’s method. About 10% or a minimum of one accession from each cluster and region was selected to develop core subset of 77 accessions. The similarity in correlation coefficients in entire collection and core subset suggest that this core subset has preserved most of the co-adapted gene complexes controlling these associations. The peanut breeders engaged in improving the genetic potential of Valencia peanuts will find this core subset useful in cultivar development

Microsatellite identification and characterization in peanut (A. hypogaea L.)

A major constraint to the application of biotechnology to the improvement of the allotetraploid peanut, or groundnut (Arachis hypogaea L.), has been the paucity of polymorphism among germplasm lines using biochemical (seed proteins, isozymes) and DNA markers (RFLPs and RAPDs). Six sequence-tagged microsatellite (STMS) markers were previously available that revealed polymorphism in cultivated peanut. Here, we identify and characterize 110 STMS markers that reveal genetic variation in a diverse array of 24 peanut landraces. The simple-sequence repeats (SSRs) were identified with a probe of two 27,648-clone genomic libraries: one constructed using PstI and the other using Sau3AI/BamHI. The most frequent, repeat motifs identified were ATT and GA, which represented 29% and 28%, respectively, of all SSRs identified. These were followed by AT, CTT, and GT. Of the amplifiable primers, 81% of ATT and 70.8% of GA repeats were polymorphic in the cultivated peanut test array. The repeat motif AT showed the maximum number of alleles per locus (5.7). Motifs ATT, GT, and GA had a mean number of alleles per locus of 4.8, 3.8, and 3.6, respectively. The high mean number of alleles per polymorphic locus, combined with their relative frequency in the genome and amenability to probing, make ATT and GA the most useful and appropriate motifs to target to generate further SSR markers for peanut

Genomics of Peanut, a Major Source of Oil and Protein

Peanut, as a source of oil and protein, is the second-most important grain legume cultivated. The perceived lack of molecular variation in the cultivated species had, until recently, resulted in a focus on characterization and mapping of wild species and on transformation of peanut with genes for improved disease resistance. With development of simple sequence repeats and potentially single nn- cleotide polymorphism-based markers and improved minicore collections, the focus is shifting towards the molecular characterization of the cultivated species. The de- velopment of large-inset libraries, expressed sequence tags. genomic clone libraries, characterized mutant collections, and hioinlrmatics is e\jiected to ads ance peanut genomics

ZEB2 regulates endocrine therapy sensitivity and metastasis in luminal a breast cancer cells through a non-canonical mechanism

PURPOSE: The transcription factors ZEB1 and ZEB2 mediate epithelial-to-mesenchymal transition (EMT) and metastatic progression in numerous malignancies including breast cancer. ZEB1 and ZEB2 drive EMT through transcriptional repression of cell-cell junction proteins and members of the tumor suppressive miR200 family. However, in estrogen receptor positive (ER +) breast cancer, the role of ZEB2 as an independent driver of metastasis has not been fully investigated. METHODS: In the current study, we induced exogenous expression of ZEB2 in ER + MCF-7 and ZR-75-1 breast cancer cell lines and examined EMT gene expression and metastasis using dose-response qRT-PCR, transwell migration assays, proliferation assays with immunofluorescence of Ki-67 staining. We used RNA sequencing to identify pathways and genes affected by ZEB2 overexpression. Finally, we treated ZEB2-overexpressing cells with 17β-estradiol (E2) or ICI 182,780 to evaluate how ZEB2 affects estrogen response. RESULTS: Contrary to expectation, we found that ZEB2 did not increase canonical epithelial nor decrease mesenchymal gene expressions. Furthermore, ZEB2 overexpression did not promote a mesenchymal cell morphology. However, ZEB1 and ZEB2 protein expression induced significant migration of MCF-7 and ZR-75-1 breast cancer cells in vitro and MCF-7 xenograft metastasis in vivo. Transcriptomic (RNA sequencing) pathway analysis revealed alterations in estrogen signaling regulators and pathways, suggesting a role for ZEB2 in endocrine sensitivity in luminal A breast cancer. Expression of ZEB2 was negatively correlated with estrogen receptor complex genes in luminal A patient tumors. Furthermore, treatment with 17β-estradiol (E2) or the estrogen receptor antagonist ICI 182,780 had no effect on growth of ZEB2-overexpressing cells. CONCLUSION: ZEB2 is a multi-functional regulator of drug sensitivity, cell migration, and metastasis in ER + breast cancer and functions through non-canonical mechanisms

Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA

Inclusive photoproduction of D*+- mesons has been measured for photon-proton centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of 37 pb^-1. Total and differential cross sections as functions of the D* transverse momentum and pseudorapidity are presented in restricted kinematical regions and the data are compared with next-to-leading order (NLO) perturbative QCD calculations using the "massive charm" and "massless charm" schemes. The measured cross sections are generally above the NLO calculations, in particular in the forward (proton) direction. The large data sample also allows the study of dijet production associated with charm. A significant resolved as well as a direct photon component contribute to the cross section. Leading order QCD Monte Carlo calculations indicate that the resolved contribution arises from a significant charm component in the photon. A massive charm NLO parton level calculation yields lower cross sections compared to the measured results in a kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure