Calmodulin-binding proteins in granule and plasma membranes from bovine chromaffin cells

Calmodulin-binding proteins in chromaffin granule membrane and chromaffin cell plasma membranes have been investigated and compared. Chromaffin granules were purified by centrifugation over a 1.7 M sucrose layer. Plasma membranes were obtained in a highly purified form by differential and isopycnic centrifugation. Enzymatic determinations of 5'-nucleotidase, a generally accepted plasma membrane marker, showed a 40-50-fold enrichment as compared to the cell homogenate. Marker enzyme studies demonstrated only minimal contamination by other subcellular organelles. After solubilization with Triton X-100, calmodulin-binding proteins were isolated from chromaffin granule membranes and plasma membranes by affinity chromatography on a calmodulin/Sepharose 4B column. On two-dimensional polyacrylamide gelelectrophoresis a prominent protein (Mr = 65,000, pI ranging from 5.1 to 6) consisting of multiple spots, was present in the calmodulin-binding fraction from chromaffin granule membranes as well as from plasma membranes. Besides this 65 kDa protein both fractions had at least four groups of proteins in common. Also, proteins typical for either preparation were observed. In the calmodulin-binding protein preparations from chromaffin granule membranes a prominent spot with Mr = 80,000 and a pH ranging from 5.0 to 5.7 was present. This protein was enzymatically and immunologically identified as dopamine-beta-monooxygenase.     

Multimodal biomarker discovery for active Onchocerca volvulus infection

The neglected tropical disease onchocerciasis, or river blindness, is caused by infection with the filarial nematode Onchocerca volvulus. Current estimates indicate that 17 million people are infected worldwide, the majority of them living in Africa. Today there are no non-invasive tests available that can detect ongoing infection, and that can be used for effective monitoring of elimination programs. In addition, to enable pharmacodynamic studies with novel macrofilaricide drug candidates, surrogate endpoints and efficacy biomarkers are needed but are non-existent. We describe the use of a multimodal untargeted mass spectrometry-based approach (metabolomics and lipidomics) to identify onchocerciasis-associated metabolites in urine and plasma, and of specific lipid features in plasma of infected individuals (O. volvulus infected cases: 68 individuals with palpable nodules; lymphatic filariasis cases: 8 individuals; non-endemic controls: 20 individuals). This work resulted in the identification of elevated concentrations of the plasma metabolites inosine and hypoxanthine as biomarkers for filarial infection, and of the urine metabolite cis-cinnamoylglycine (CCG) as biomarker for O. volvulus. During the targeted validation study, metabolite-specific cutoffs were determined (inosine: 34.2 ng/ml; hypoxanthine: 1380 ng/ml; CCG: 29.7 ng/ml) and sensitivity and specificity profiles were established. Subsequent evaluation of these biomarkers in a non-endemic population from a different geographical region invalidated the urine metabolite CCG as biomarker for O. volvulus. The plasma metabolites inosine and hypoxanthine were confirmed as biomarkers for filarial infection. With the availability of targeted LC-MS procedures, the full potential of these 2 biomarkers in macrofilaricide clinical trials, MDA efficacy surveys, and epidemiological transmission studies can be investigated.     

Analysis of bruchid resistance in the wild common bean accession G02771: no evidence for insecticidal activity of arcelin 5

Arcelins are abundant seed storage proteins thought to be implicated in the resistance of wild Phaseolus vulgaris (L.) genotypes against Zabrotes subfasciatus (Boheman), an important storage insect pest of common bean. Here, the insecticidal activity of the arcelin-5 variant that is present in the highly resistant P. vulgaris accession G02771 was investigated. No correlation could be established between the presence of arcelin 5 and the insecticidal effects observed in G02771 seeds. Insect feeding assays with artificial seeds into which purified arcelin-5 protein was incorporated and with transgenic P. acutifolius (A. Gray) seeds in which the arcelin-5 genes were expressed, showed that the presence of arcelin-5 proteins, even at elevated levels, was not sufficient to achieve adequate resistance against Z. subfasciatus. The same might apply to other arcelin variants. Nevertheless, as resistance is clearly closely linked to the presence of the arcelin-1 or arcelin-5 locus, arcelins remain useful markers in breeding programmes aimed at introgressing high levels of resistance to Z. subfasciatus in P. vulgaris cultivars.     

Antimicrobial peptides from Amaranthus caudatus seeds with sequence homology to the cysteine/glycine-rich domain of chitin-binding proteins.

Two antimicrobial peptides (Ac-AMP1 and Ac-AMP2) were isolated from seeds of amaranth (Amaranthus caudatus), and their physicochemical and biological properties were characterized. On the basis of fast atom bombardment mass spectroscopy, Ac-AMP1 and Ac-AMP2 have monoisotopic molecular masses of 3025 and 3181, respectively. Both proteins have pI values above 10. The amino acid sequence of Ac-AMP1 (29 residues) is identical to that of Ac-AMP2 (30 residues), except that the latter has 1 additional residue at the carboxyl terminus. The sequences are highly homologous to the cysteine/glycine-rich domain occurring in many chitin-binding proteins. Both Ac-AMP1 and Ac-AMP2 bind to chitin in a reversible way. Ac-AMP1 and Ac-AMP2 inhibit the growth of different plant pathogenic fungi at much lower doses than other known antifungal chitin-binding proteins. In addition, they show some activity on Gram-positive bacteria. The antimicrobial effect of Ac-AMP1 and Ac-AMP2 is strongly antagonized by cations.     

The economics and greenhouse gas balance of land conversion to Jatropha: the case of Tanzania

Due to higher oil prices, abundance of labor and suitable land and its stable political climate, Tanzania attracted many investments in Jatropha. Although several studies on Jatropha's economic potential are available, its true economics are still uncertain. This paper aims to add to the growing body of knowledge on the socio‐economic performance of the Jatropha system by (i) studying the economic potential (net present value – NPV) of the current most prevailing Jatropha system for Tanzanian farmers and its regional differences, by (ii) making a greenhouse gas (GHG) balance and its economic value of the Jatropha activities on regional level, and by (iii) calculating break‐even thresholds for yield and seed price. Therefore, regional yield modeling, regional life‐cycle assessment, and NPV calculations based on Monte Carlo simulations, each with its set of assumptions, are combined. This study shows positive economic potential of Jatropha cultivation in most of the Tanzanian regions. However, the results also show that 13 of 20 Tanzanian regions will not attain a net positive GHG balance within 10 years. This indicates that the environmental impacts might be more restrictive for Jatropha's sustainability potential in Tanzania than the socio‐economic potential. These results are based on the combination of three models, which consists of strong interdisciplinary modeling work. However, this modeling also contains simplifications (e.g., no opportunity cost for ‘marginal’ land) and uncertainties (e.g., using globally modeled potential yield estimations), which have to be considered in the interpretation of the results.     

Genomic analysis of SARS-CoV-2 reveals local viral evolution in Ghana

The confirmed case fatality rate for the coronavirus disease 2019 (COVID-19) in Ghana has dropped from a peak of 2% in March to be consistently below 1% since May 2020. Globally, case fatality rates have been linked to the strains/clades of circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within a specific country. Here we present 46 whole genomes of SARS-CoV-2 circulating in Ghana, from two separate sequencing batches: 15 isolates from the early epidemic (March 12–April 1 2020) and 31 from later time-points ( 25–27 May 2020). Sequencing was carried out on an Illumina MiSeq system following an amplicon-based enrichment for SARS-CoV-2 cDNA. After genome assembly and quality control processes, phylogenetic analysis showed that the first batch of 15 genomes clustered into five clades: 19A, 19B, 20A, 20B, and 20C, whereas the second batch of 31 genomes clustered to only three clades 19B, 20A, and 20B. The imported cases (6/46) mapped to circulating viruses in their countries of origin, namely, India, Hungary, Norway, the United Kingdom, and the United States of America. All genomes mapped to the original Wuhan strain with high similarity (99.5–99.8%). All imported strains mapped to the European superclade A, whereas 5/9 locally infected individuals harbored the B4 clade, from the East Asian superclade B. Ghana appears to have 19B and 20B as the two largest circulating clades based on our sequence analyses. In line with global reports, the D614G linked viruses seem to be predominating. Comparison of Ghanaian SARS-CoV-2 genomes with global genomes indicates that Ghanaian strains have not diverged significantly from circulating strains commonly imported into Africa. The low level of diversity in our genomes may indicate lower levels of transmission, even for D614G viruses, which is consistent with the relatively low levels of infection reported in Ghana.     

Bud set in poplar--genetic dissection of a complex trait in natural and hybrid populations

? The seasonal timing of growth events is crucial to tree distribution and conservation. The seasonal growth cycle is strongly adapted to the local climate that is changing because of global warming. We studied bud set as one cornerstone of the seasonal growth cycle in an integrative approach. ? Bud set was dissected at the phenotypic level into several components, and phenotypic components with most genetic variation were identified. While phenotypic variation resided in the timing of growth cessation, and even so more in the duration from growth cessation to bud set, the timing of growth cessation had a stronger genetic component in both natural and hybrid populations. ? Quantitative trait loci (QTL) were identified for the most discriminative phenotypic bud-set components across four poplar pedigrees. The QTL from different pedigrees were recurrently detected in six regions of the poplar genome. ? These regions of 1.83-4.25 Mbp in size, containing between 202 and 394 genes, form the basis for further molecular-genetic dissection of bud set.