hGrb10␣ (previously named Grb-IR) is a Src-homology 2 domain-containing protein that binds with high affinity to the tyrosine-phosphorylated insulin receptor and insulin-like growth factor-1 receptor. At least two isoforms of human Grb10, (hGrb10␣ and hGrb10␤), which differ in the pleckstrin homology (PH) domain and the N-terminal sequence, have previously been identified in insulin target tissues such as human skeletal muscle and fat cells. Here we report the cloning of the third isoform of the hGrb10 family (hGrb10␥) from human skeletal muscle and its localization to human chromosome 7. We have also determined the human chromosome localization of Grb7 to 17q21-q22 and Grb14 to chromosome 2. hGrb10␥ contains an intact PH domain and an N-terminal sequence that is present in hGrb10␣ but absent in hGrb10␤. RNase protection assays and Western blot analysis showed that hGrb10␣ and hGrb10␥ are differentially expressed in insulin target cells including skeletal muscle, liver, and adipocyte cells. hGrb10␥ is also expressed in HeLa cells and various breast cancer cell lines. The protein bound with high affinity to the insulin receptor in cells, and the interaction was dependent on the tyrosine phosphorylation of the receptor. hGrb10␥ also underwent insulin-stimulated membrane translocation and serine phosphorylation. hGrb10␥ phosphorylation was inhibited by PD98059, a specific inhibitor of mitogen-activated protein kinase kinase, and wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase. Taken together, our data suggest that hGrb10 isoforms are potential downstream signaling components of the insulin receptor tyrosine kinase and that the PH domain may play an important role in the involvement of these isoforms in signal transduction pathways initiated by insulin and other growth factors.Insulin stimulates and regulates cell growth and metabolism by binding to its receptor on the cell membrane. The binding of insulin to the insulin receptor (IR) 1 results in receptor autophosphorylation and receptor tyrosine kinase activation, followed by tyrosine phosphorylation of various cellular substrates including a 185-kDa protein called the IR substrate 1 or IRS-1 (1, 2). Tyrosine phosphorylation of IRS-1 creates docking sites for multiple downstream signaling molecules with specific sequence motifs. One of these functional motifs found in signaling proteins is the Src homology 2 (SH2) domain. The SH2 domain is a sequence of approximately 100 amino acids that binds with high affinity to phosphotyrosine-containing proteins (3). Another functional domain is the pleckstrin homology (PH) domain that has been suggested to play important roles in protein-protein and protein-lipid interactions (4 -6).Although numerous studies have shown that IRS-1 is critical in IR signal transduction, evidence does exist that other proteins may also be involved to transduce a signal from the IR to downstream targets (2). In a search for signaling molecules involved in IR signaling, we used the yeast two-hybrid system to find proteins that i...

a b s t r a c tThe objective was to determine the effect of time and temperature on the concentration of bioactive compounds during germination of Brazilian soybean cultivar BRS 258. The concentration of bioactive compounds was optimized using Response Surface Methodology, with a 2 2 central composite rotational design and germination time and temperature as independent variables. Germination was carried out in a germination chamber, using paper in trays containing 500 g of seeds. Germination temperature and time modified the concentrations of bioactive compounds within the ranges studied. An increase in germination time at 25°C decreased the concentration of Bowman-Birk inhibitor, lectin and lipoxygenase. After 63 h of germination, a temperature increase from 20°C to 30°C resulted in a decrease of lipoxygenase activity by 22.5%. Optimal increases in the concentrations of isoflavone aglycones (daidzein and genistein) and saponin glycosides were observed with a 63 h germination time at 30°C. Both germination time and temperature had an influence on the composition and concentration of bioactive compounds in germinated soybean flour. Equations determined can be used to predict concentrations of bioactive compounds in germinated soybeans in relation to climate changes and thus optimize their potential use in human health and nutrition.

Seeds of BRS 213 soybean cultivar were germinated for 72 h at 25c. Samples were collected and analyzed every 6 h during germination. b-glucosidase activity increased 3.3-fold in radicles and 2.3-fold in cotyledons. In the radicles, there was a significant decrease in total isoflavone content (6.3-fold), while for malonyl forms, daidzin and glycitin, there was a decrease of 5.0-to 10.0-fold. Daidzein did not vary significantly during germination, while genistein and glycitein were detected at some germination times. In the cotyledons, there was an increase in total isoflavone content (2.4-fold), malonylgenistin (2.6-fold) and 3.3-fold increases for malonyldaidzin. Genistin and daidzin did not vary significantly during germination and genistein was only detected 0 and 6 h after incubation. 4 Corresponding

The influence of temperature on the fatty acid composition of the oils from conventional and high oleic sunflower genotypes grown in tropical regions was evaluated under various environmental conditions in Brazil (from 0° S to 23° S). The amounts of the oleic, linoleic, palmitic and stearic fatty acids from the sunflower oil were determined using gas chromatography (GC). The environment exhibited little influence on the amounts of oleic and linoleic fatty acids in high oleic genotypes of sunflower. In conventional genotypes, there was broad variation in the average amounts of these two fatty acids, mainly as a function of the minimum temperature. Depending on the temperature, especially during the maturation of the seeds, the amount of oleic acid in the oil of conventional sunflower genotypes could exceed 70 %. Higher temperatures led to average increases of up to 35 % for this fatty acid. Although the minimum temperature had the strongest effect on the fatty acid composition, locations at the same latitude with different minimum temperatures displayed similar values for both oleic acid and linoleic acid. Furthermore, minimum temperature had little influence on the amounts of palmitic and stearic fatty acids in the oil.

The introduction of cultivars with earlier development and greater productivity has raised questions about the effect of management practices on soybean [Glycine max (L.) Merr] yield in a no‐till (NT) system. The objective of the study was to evaluate the interaction between N fertilization, row spacing, and plant density on photosynthetic index, yield components, yield, and nutritional status of soybean–wheat (Triticum aestivum L.) intercropping. For soybean cultivation, three N rates, three row spacing, and three planting densities were assessed during two growing seasons, while for wheat, 17.5‐cm row spacing and no N fertilization were used. No significant effects of row spacing and plant density were detected. The yields for 0 and 40 kg N ha−1 rates were similar, while applying 20 kg N ha−1 reduced, on average, soybean yield by 14.5%. The planting densities, row spacing, and N rates did not affect wheat yield, or oil and protein content in soybean seeds. Soil temperature (ST), intercellular carbon dioxide concentration (Ci), and intrinsic water use efficiency (IWUE) increased, while plant height, chlorophyll content (CC), and transpiration rate (Trmmol) decreased with increasing spacing of soybean. Plant density changed ST, Ci, chlorophyll content, and stomatal conductance (gs). Leaf tissue analysis indicated adequate nutrient levels in soybean and wheat. The current management practice with 50‐cm row spacing, no N fertilization to complement biological nitrogen fixation (BNF), and 333,000 plants ha−1 is adequate for soybean cultivation, while N supplied from soil organic matter (SOM) and BNF is sufficient to meet requirements of associated wheat crops.