IndraLab
Statements
"The activation of stat-3 is regulated by phosphorylation of tyrosine 705 by receptor and nonreceptor protein tyrosine kinases these include epidermal growth factor receptor (egfr) kinase,92 src,5 janus-activated kinases (jak), and extracellular signal-regulated kinase (erk)a constitutively active galpha16 mutant, galpha16ql, stimulated stat3-dependent luciferase activity as well as the phosphorylation of stat3 at both tyr705 and ser727. Galpha16ql-induced stat3 activation was enhanced by overexpression of extracellular signal-regulated kinase 1 (erk1"
"PTP1B was able to dephosphorylate activated JAK2 and STAT3 in vitro, whereas either no or a minimal effect was observed with cluster of differentiation 45 (CD45), PTPalpha and leukocyte antigen-related (LAR). By utilisation of a selective PTP1B inhibitor, the leptin-induced STAT3 activation was enhanced in cells. In conclusion, these results suggested that the negative regulatory role of PTP1B on leptin signalling is mediated through a direct and selective dephosphorylation of the two signalling molecules, JAK2 and STAT3."
"Upon ligand binding, IL-2R , IL-6R or LeptinR , IFN-_R , IFN-_R and PRLR or growth hormone (GH) receptor associated JAKs become activated. These JAKs mediate phosphorylation of specific tyrosine residues and recruit STATs. Activated STATs are released from the receptor and translocate to the nucleus. PTP1B dephosphorylates JAK2, TYK2 and STAT5 . The 45-kDa form of TC-PTP was shown to dephosphorylate JAK1 and JAK3 as well as STAT1, STAT3 and STAT5."
"In the present study, we have delineated the mechanism by which Galpha16 stimulates STAT3 in human embryonic kidney 293 cells. A constitutively active Galpha16 mutant, Galpha16QL, stimulated STAT3-dependent luciferase activity as well as the phosphorylation of STAT3 at both Tyr705 and Ser727.The involvement of tyrosine kinases such as c-Src and Janus kinase 2 and 3 (JAK2 and JAK3) in Galpha16QL-induced activation of STAT3 was illustrated by the combined use of selective inhibitors and dominant negative mutants."
"The activation of stat-3 is regulated by phosphorylation of tyrosine 705 by receptor and nonreceptor protein tyrosine kinases these include epidermal growth factor receptor (egfr) kinase,92 src,5 janus-activated kinases (jak), and extracellular signal-regulated kinase (erk)a constitutively active galpha16 mutant, galpha16ql, stimulated stat3-dependent luciferase activity as well as the phosphorylation of stat3 at both tyr705 and ser727. Galpha16ql-induced stat3 activation was enhanced by overexpression of extracellular signal-regulated kinase 1 (erk1"
"Activation of Stat1 and Stat3 by FGFR derivatives. Lysates of 293T cells transfected as indicated were analysed by Western blotting using Phospho-Stat1 (Y701) antisera (top) or Stat1 antisera (bottom). (b) The same lysates in (a) were re-examined for phosphorylated Stat3 by Western blotting with Phospho-Stat3 (Y705) (top). all three FGFR family members examined here are able to lead to Stat activation. Expression of the 'TDII-like' derivatives of FGFR1, FGFR3, and FGFR4, as well as myrR1-WT, led to phosphorylation of both Stat1 and Stat3."
"Activation of Stat1 and Stat3 by FGFR derivatives. Lysates of 293T cells transfected as indicated were analysed by Western blotting using Phospho-Stat1 (Y701) antisera (top) or Stat1 antisera (bottom). (b) The same lysates in (a) were re-examined for phosphorylated Stat3 by Western blotting with Phospho-Stat3 (Y705) (top). all three FGFR family members examined here are able to lead to Stat activation. Expression of the 'TDII-like' derivatives of FGFR1, FGFR3, and FGFR4, as well as myrR1-WT, led to phosphorylation of both Stat1 and Stat3."
"Inactive cytoplasmic STATs are recruited to the activated receptor by docking of the STAT SH2 domain to selected receptor tyrosine phosphopeptides, where they are in turn phosphorylated on a single tyrosine by Jak kinases. Has been identified tyrosine 705 of Stat3 as the likely site of phosphorylation by Jak kinases during signal transduction."