Protein tyrosine phosphatases (PTPs) are key regulatory factors in inflammatory signaling pathways. Although PTPs have been extensively studied, little is known about their role in neuroinflammation. In the present study, we examined the expression of 6 different PTPs (PTP1B, TC-PTP, SHP2, MEG2, LYP, and RPTPβ) and their role in glial activation and neuroinflammation. All PTPs were expressed in...

BACKGROUND/AIMS The linoleic acid derivative DCP-LA selectively activates PKCε and inhibits protein phosphatase 1 (PP1). In the present study, we have newly synthesized phosphatidyl-ethanolamine, -serine, -choline, and -inositol containing DCP-LA at the α and β position (diDCP-LA-PE, -PS, PC, and -PI, respectively), and examined the effects of these compounds on activities of PKC isozymes and p...

Sargassum serratifolium C. Agardh (Phaeophyceae, Fucales) is a marine brown alga that belongs to the family Sargassaceae. It is widely distributed throughout coastal areas of Korea and Japan. S. serratifolium has been found to contain high concentrations of plastoquinones, which have strong anti-cancer, anti-inflammatory, antioxidant, and neuroprotective activity. This study aims to investigate...

The protein tyrosine phosphatase PTP1B, previously recognized for its role in downregulating insulin and leptin signaling, has now been shown to function as a positive regulator of signaling events associated with breast tumorigenesis. Inhibitors of PTP1B that have been developed as drug candidates for treatment of diabetes and obesity may offer new avenues for the treatment of breast cancer.

PTP1B is an endoplasmic reticulum (ER) anchored enzyme whose access to substrates is partly dependent on the ER distribution and dynamics. One of these substrates, the protein tyrosine kinase Src, has been found in the cytosol, endosomes, and plasma membrane. Here we analyzed where PTP1B and Src physically interact in intact cells, by bimolecular fluorescence complementation (BiFC) in combinati...

Leptin regulates energy balance through central circuits that control food intake and energy expenditure, including proopiomelanocortin (POMC) neurons. POMC neuron-specific deletion of protein tyrosine phosphatase 1B (PTP1B) (Ptpn1(loxP/loxP) POMC-Cre), a negative regulator of CNS leptin signaling, results in resistance to diet-induced obesity and improved peripheral leptin sensitivity in mice,...

We have developed two bioluminescence resonance energy transfer (BRET)-based approaches to monitor 1) ligand-induced conformational changes within partially purified insulin-like growth factor-1 (IGF-1) receptors (IGF1R) and 2) IGF1R interaction with a substrate-trapping mutant of protein tyrosine phosphatase 1B (PTP1B-D181A) in living cells. In the first assay, human IGF1R fused to Renilla ren...

Interactions between E-cadherin, beta-catenin and PTP1B (protein tyrosine phosphatase 1B) are crucial for the organization of AJs (adherens junctions) and epithelial cell-cell adhesion. In the present study, the effect of acetaldehyde on the AJs and on the interactions between E-cadherin, beta-catenin and PTP1B was determined in Caco-2 cell monolayers. Treatment of cell monolayers with acetalde...

Activated EGFR (epidermal growth factor receptor) undergoes ESCRT (endosomal sorting complex required for transport)-mediated sorting on to ILVs (intraluminal vesicles) of endosomes before degradation in the lysosome. Sorting of endocytosed EGFR on to ILVs removes the catalytic domain of the EGFR from the cytoplasm, resulting in termination of receptor signalling. EGFR signalling is also subjec...