Characterization of intracellular signals via tyrosine 1062 in RET activated by glial cell line-derived neurotrophic factor.
Glial cell line derived neurotrophic factor (GDNF) signals through a multicomponent receptor complex consisting of RET receptor tyrosine kinase and a member of GDNF family receptor alpha (GFRalpha). Recently, it was shown that tyrosine 1062 in RET represents a binding site for SHC adaptor proteins and is crucial for both RAS/mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3-K)/AKT signaling pathways. In the present study, we characterized how these two pathways diverge from tyrosine 1062, using human neuroblastoma and primitive neuroectodermal tumor cell lines expressing RET at high levels. In response to GDNF stimulation, SHC bound to GAB1 and GRB2 adaptor proteins as well as RET, and SHC and GAB1 were highly phosphorylated on tyrosine. The complex formation consisting of SHC, GAB1 and GRB2 was almost abolished by replacement of tyrosine 1062 in RET with phenylalanine. Tyrosine-phosphorylated GAB1 was also associated with p85 subunit of PI3-K, resulting in PI3-K and AKT activation, whereas SHC-GRB2-SOS complex was responsible for the RAS/ERK signaling pathway. These results suggested that the RAS and PI3-K pathways activated by GDNF bifurcate mainly through SHC bound to tyrosine 1062 in RET. Furthermore, using luciferase reporter-gene assays, we found that the RAS/ERK and PI3-K signaling pathways are important for activation of CREB and NF-kappaB in GDNF-treated cells, respectively. Oncogene (2000) 19, 4469 - 4475.
Hayashi
H
H
Department of Pathology, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Ichihara
M
M
Iwashita
T
T
Murakami
H
H
Shimono
Y
Y
Kawai
K
K
Kurokawa
K
K
Murakumo
Y
Y
Imai
T
T
Funahashi
H
H
Nakao
A
A
Takahashi
M
M
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000730:Androstadienes / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051380:GRB2 Adaptor Protein; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D016328:NF-kappa B / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000494:pharmacology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D055765:Shc Signaling Adaptor Proteins; D015398:Signal Transduction; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism; D000077191:Wortmannin; D018631:ras Proteins / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000730:Androstadienes; D017362:Cyclic AMP Response Element-Binding Protein; D029721:Drosophila Proteins; D004791:Enzyme Inhibitors; D051380:GRB2 Adaptor Protein; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D019950:Mitogen-Activated Protein Kinase 1; D016328:NF-kappa B; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins; D017346:Protein Serine-Threonine Kinases; D011506:Proteins; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014443:Tyrosine; D000077191:Wortmannin; D018631:ras Proteins; C098587:GAB1 protein, human; C495039:GDNF protein, human; C495948:GRB2 protein, human; C528024:SHC1 protein, human; C416649:Ret protein, Drosophila; C494918:AKT1 protein, human