SHP-1 Associates with Both Platelet-derived Growth Factor Receptor and the p85 Subunit of Phosphatidylinositol 3-Kinase*

The Src homology 2 (SH2)-containing protein tyrosine phosphatase 1, SHP-1, is highly expressed in all hematopoietic cells as well as in many non-hematopoietic cells, particularly in some malignant epithelial cell lines. In hematopoietic cells, SHP-1 negatively regulates multiple cytokine receptor pathways. The precise function and the targets of SHP-1 in non-hematopoietic cells, however, are largely unknown. Here we demonstrate that SHP-1 associates with both the tyrosine-phosphorylated platelet-derived growth factor (PDGF) receptor and the p85 subunit of phosphatidylinositol 3-kinase in MCF-7 and TRMP cells. Through the use of mutant PDGF receptors and performing peptide competition for immunoprecipitation, it was determined that SHP-1 independently associates with the PDGF receptor and p85 and that its N-terminal SH2 domain is directly responsible for the interactions. Overexpression of SHP-1 in TRMP cells transfected with the PDGF receptor markedly inhibited PDGF-induced c-fos promoter activation, whereas the expression of three catalytically inactive SHP-1 mutants increased the c-fos promoter activation in response to PDGF stimulation. These results indicate that SHP-1 might negatively regulate PDGF receptor-mediated signaling in these cells. Identification of the association of SHP-1 with the PDGF receptor and p85 in MCF-7 and TRMP cells furthers our understanding of the function of SHP-1 in non-hematopoietic cells

Evaluation of functional attributes and storage stability of novel juice blends from baobab, pineapple, and black-plum fruits

This research article was published by Heliyon, 2022Several under-utilized tropical fruits have exceptional micronutrients and phytochemical composition with the potential to contribute to the nutrition of people and also enhance food security. This study was carried out to evaluate the quality attributes and storage stability of juice blends of baobab (Adansonia digitata), pineapple (Ananas comosus), and black-plum (Syzygium cumini) fruits for use as functional beverages. Juice blends were analyzed for physicochemical, antioxidant, and sensory properties. Mineral compositions and storage stability of the pasteurized juice blends at 4 C for 4 weeks were also investigated. Results showed that the vitamin C contents of individual juices synergistically contributed to the high values observed in the blends (317.45–414.51 mg/L). Juice blends of baobab, pineapple, and black-plum fruits are good sources of calcium (57–153 mg/L), magnesium (71–130 mg/L) and antioxidants (ascorbic acid, total polyphenol contents (65–104 mg GAE/100 mL), scavenging ability (105.97–359.71 μmol TE/100 mL), and reducing potential (1376–1829 μMFe2þ L) the consumption of which will promote human health. Blending enhanced the sensory qualities of the individual juices with improved taste and consumer acceptability. The juice blends kept well for two weeks at 4 C though the color becomes less intense at the end of the storage period. These findings suggest that baobab-fruit pulp, pineapple, and black-plum fruits can be major ingredients in producing a consumer acceptable anti-oxidant rich functional beverage for optimal benefits to consumers

SHP-1 associates with both platelet-derived growth factor receptor and the p85 subunit of phosphatidylinositol 3-kinase

UI - 98123150NRC publication: Ye