The structure of a human p110alpha/p85alpha complex elucidates the effects of oncogenic PI3Kalpha mutations

PIK3CA, one of the two most frequently mutated oncogenes in human tumors, codes for p110alpha, the catalytic subunit of a phosphatidylinositol 3-kinase, isoform alpha (PI3Kalpha, p110alpha/p85). Here, we report a 3.0 angstrom resolution structure of a complex between p110alpha and a polypeptide containing the p110alpha-binding domains of p85alpha, a protein required for its enzymatic activity. The structure shows that many of the mutations occur at residues lying at the interfaces between p110alpha and p85alpha or between the kinase domain of p110alpha and other domains within the catalytic subunit. Disruptions of these interactions are likely to affect the regulation of kinase activity by p85 or the catalytic activity of the enzyme, respectively. In addition to providing new insights about the structure of PI3Kalpha, these results suggest specific mechanisms for the effect of oncogenic mutations in p110alpha and p85alpha.     

Conservation and use of genetic resources of cacao (Theobroma cacao L.) by gene banks and nurseries in six Latin American countries

Genetic Resources and Crop Evolution - Cacao (Theobroma cacao L.) is among the most important cash crops in tropical countries. The existing cacao genetic diversity represents a key resource to...     

Effects of Lime‐Cooking on Carotenoids Present in Masa and Tortillas Produced from Different Types of Maize

Yellow and white maize kernels, masas, tortillas, and nejayote solids were analyzed in terms of lutein, zeaxanthin, cryptoxanthin, β‐carotene, and lipophilic antioxidant (AOX) capacity. The germplasm analyzed included two normal yellow maize, two high‐carotenoid genotypes, and one white for comparison purposes. In general, the yellow maize required 34% more lime‐cooking time compared with the white counterpart. Lime‐cooking significantly changed the extractability of carotenoids in masa and tortillas. No carotenoids were detected in the steepwater or nejayote. The lipophilic AOX activity increased 280‐fold from kernel to masa, but only 70% was retained in the baked tortillas. When masa was baked into tortillas, less than 10% of the carotenoids were retained because of the high temperatures used during baking. Interestingly, tortillas made with the maize kernels with the highest carotenoid content did not have the highest amount of these phytochemicals. Therefore, maize varieties should be evaluated based on the carotenoid content in finished food products instead of the amounts originally found in raw kernels.     

Stability of sterols in phytosterol-enriched milk under different heating conditions

Commercially available phytosterol-enriched milk was subjected to usual and drastic heating conditions to evaluate the stability of the sterols at different treatments. Products showed 422.2 mg of phytosterols/100 g of milk and 132 microg of sterol oxidation products (SOPs)/g of fat (277 microg of SOPs/100 g of milk). Schaal oven conditions (24 h/65 degrees C, equivalent to 1 month of storage at room temperature) reduced the phytosterol content by only 4%. Drastic heating treatments (2 min of microwave heating at 900 W or 15 min of electrical heating at 90 degrees C) led to a 60% decrease of total phytosterol content, with a significant increase of TBARs. The oxysterol amount under those conditions (which was higher in microwave-treated samples) was lower than expected, probably because of the degradation of the oxidation products. Usual heating conditions (1.5 min of microwaves) maintained phytosterol content on physiologically active values (301 mg/100 g of milk) with oxidation percentages around 0.12-0.40% for phytosterols and 1.13% for cholesterol.     

Ancestral developmental potential facilitates parallel evolution in ants

Complex worker caste systems have contributed to the evolutionary success of advanced ant societies; however, little is known about the developmental processes underlying their origin and evolution. We combined hormonal manipulation, gene expression, and phylogenetic analyses with field observations to understand how novel worker subcastes evolve. We uncovered an ancestral developmental potential to produce a "supersoldier" subcaste that has been actualized at least two times independently in the hyperdiverse ant genus Pheidole. This potential has been retained and can be environmentally induced throughout the genus. Therefore, the retention and induction of this potential have facilitated the parallel evolution of supersoldiers through a process known as genetic accommodation. The recurrent induction of ancestral developmental potential may facilitate the adaptive and parallel evolution of phenotypes.     

Differential antigen processing by dendritic cell subsets in vivo

Dendritic cells (DCs) process and present self and foreign antigens to induce tolerance or immunity. In vitro models suggest that induction of immunity is controlled by regulating the presentation of antigen, but little is known about how DCs control antigen presentation in vivo. To examine antigen processing and presentation in vivo, we specifically targeted antigens to two major subsets of DCs by using chimeric monoclonal antibodies. Unlike CD8+ DCs that express the cell surface protein CD205, CD8- DCs, which are positive for the 33D1 antigen, are specialized for presentation on major histocompatibility complex (MHC) class II. This difference in antigen processing is intrinsic to the DC subsets and is associated with increased expression of proteins involved in MHC processing.     

Development and application of a capillary electrophoresis method for the determination of ellagic acid in E. globulus wood and in filtrates from E. globulus kraft pulp

A capillary zone electrophoresis (CZE) method for simple and rapid determination of ellagic acid (EA) in Eucalyptus globulus wood and in the filtrate from unbleached kraft pulp has been developed. This is the first application of CZE for the detection of EA in industrial streams from cellulosic pulp production. The EA determinations in wood extractives and in pulp filtrates were succeeded only after sample acidification. This new CZE analytical procedure allowed reliable determinations of EA in E. globulus wood (1.1 ± 0.6 g kg^?1 of dry wood) and in the filtrates from unbleached kraft pulp (98 ± 0.7 mg L^?1). Gas chromatography–mass spectrometry was used as a reference method for the quantification of EA in industrial samples.     

Evaluation of gross protein and lipid requirements in formulated feed for honey gourami,Trichogaster chuna (Hamilton 1822)

Gross protein and fat requirements in formulated feeds designed for the honey gourami, Trichogaster chuna (initial weight 1.34–1.38 g), were investigated. Feeds containing 30%, 40%, and 50% protein and 6% and 9% lipid at each protein level were tested. Protein and energy sources used were from fishmeal, shrimp meal, clam meal, soy flour, and wheat flour. An equal mixture of crude sardine oil and groundnut oil was used as the source of lipids. Comparison of the whole gourami amino acid profiles before and after the dietary treatments indicated a relative decline in all amino acids except methionine and lysine. Fatty acid profiles of whole individuals after dietary treatment showed a substantial increase in monounsaturated fatty acids relative to the initial fatty acid profiles. No significant differences were observed in fish growth between dietary treatments (p > .05). Feeds containing 30% protein and 6% lipid were found to be adequate for normal growth, while feeds with 40% protein and 6% lipid were seen to help accelerate growth and reproduction. In this study, protein and lipid levels required for regular maintenance, sexual maturation, and spawning of aquarium‐reared gourami were established.