Cellular Physiology and Biochemistry | |
PTP1B Inhibition Causes Rac1 Activation by Enhancing Receptor Tyrosine Kinase Signaling | |
关键词: Protein tyrosine phosphatase 1B; Phosphatidylinositol 3 kinase; 3-Phosphoinositide-dependent protein kinase-1; Akt; Rac1; | |
DOI : 10.1159/000358679 | |
学科分类:分子生物学,细胞生物学和基因 | |
来源: S Karger AG | |
【 摘 要 】
Background/Aims The present study investigated the signaling pathway underlying Rac1 activation induced by the linoleic acid derivative 8-[2-(2-pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA). Methods Activity of protein tyrosine phosphatase 1B (PTP1B) was assayed under cell-free conditions. Western blot was carried out to quantify phosphorylation of insulin receptor substrate-1 (IRS-1) and Akt in PC-12 cells. Rac1 activity was monitored in the föerster resonance energy transfer (FRET) analysis using living and fixed PC-12 cells. Results DCP-LA markedly suppressed PTP1B activity in a concentration (100 pM-100 µM)-dependent manner. In the DCP-LA binding assay, fluorescein-conjugated DCP-LA produced a single fluorescent signal band at 60 kDa, corresponding to the molecule of PTP1B, and the signal was attenuated or abolished by co-treatment or pretreatment with non-conjugated DCP-LA. DCP-LA significantly enhanced nerve growth factor (NGF)-stimulated phosphorylation of IRS-1 at Tyr1222 and Akt1/2 at Thr308/309 and Ser473/474 in PC-12 cells. In the FRET analysis, DCP-LA significantly enhanced NGF-stimulated Rac1 activation, which is abrogated by the phosphatidylinositol 3 kinase (PI3K) inhibitor wortmannin, the 3-phosphoinositide-dependent protein kinase-1 (PDK1) inhibitor BX912, or the Akt inhibitor MK2206. Conclusion The results of the present study show that DCP-LA-induced PTP1B inhibition, possibly through its direct binding, causes Rac1 activation by enhancing a pathway along a receptor tyrosine kinase (RTK)/IRS-1/PI3K/Akt/Rac1 axis.
【 授权许可】
CC BY-NC-ND
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
RO201904037337223ZK.pdf | 1895KB | download |