Possible Interaction: Tyrosine and Leptin

“In Fao cells, leptin alone had no effects on the insulin signaling pathway, but leptin pretreatment transiently enhanced insulin-induced tyrosine phosphorylation and PI 3-kinase binding to IRS-1, while producing an inhibition of tyrosine phosphorylation and PI 3-kinase binding to IRS-2.”

“The phosphorylation of the tyrosine is regulated by insulin and leptin molecules.”

“ Leptin induced tyrosine and serine phosphorylation of STAT1 and STAT3, both of which were suppressed by AG490, and serine phosphorylation was also suppressed by SB202190.”

“We found that leptin , even at as low as 0.1 ng/mL, induced significant tyrosine phosphorylation of epidermal growth factor receptor (EGFR).”

“These findings suggest that signaling pathway other than JAK STAT tyrosine phosphorylation (ie PLC and calcium) may be involved in mediating the prothrombotic action of leptin.”

“In this report, we demonstrate for the first time, that leptin is able to induce the tyrosine phosphorylation of the SH(2) containing protein SHC.”

“Thus, leptin dose-dependently stimulates tyrosine and threonine phosphorylation of MAPK in mononuclear cells.”

“We have found that leptin receptor, IRS-1 and the RNA-binding protein Sam68 are tyrosine phosphorylated upon leptin challenge in a dose-dependent manner.”

“Moreover, leptin stimulated tyrosine phosphorylation of the RNA binding protein Sam68 and its association with STAT-3.”

“ Leptin (50-200 nM) significantly increased tyrosine phosphorylation of STAT cytoplasmic transcription factors STAT3 and STAT5b in a dose-dependent manner and produced a gel-shift with STAT3- and STAT5-specific oligonucleotides.”

“We found that leptin caused the tyrosine phosphorylation of several proteins in human renal cell carcinoma cells, ACHN cells, in which STAT-1, but neither STAT-3 nor STAT-5, was involved.”