Constitutively active Src facilitates NGF-induced phosphorylation of TrkA and causes enhancement of the MAPK signaling in SK-N-MC cells.
Here we investigated a biological association of constitutively active Src with TrkA in SK-N-MC human neuroblastoma cells. Activation of TrkA and extracellular signal-regulated kinase (ERK) by nerve growth factor (NGF) was inhibited by pretreatment with PP2, an inhibitor of Src family kinases. Moreover, NGF-induced phosphorylation of TrkA and ERK was also attenuated by the transfection with a dominant-negative src construct. On the other hand, the transfection with a constitutively active src construct enhanced these phosphorylations. In addition, we showed that active Src phosphorylates TrkA directly in vitro, and that Src associates with TrkA through Grb2 after NGF stimulation. These results suggest that constitutively active Src that associates with TrkA through Grb2 after NGF stimulation participates in TrkA phosphorylation and in turn enhances the mitogen-activated protein kinase signaling in SK-N-MC cells.
Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8572, Japan.
Akinori
A
Tsuruda
Shingo
S
Suzuki
Takaaki
T
Maekawa
Syuichi
S
Oka
D015153:Blotting, Western; D045744:Cell Line, Tumor; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D020932:Nerve Growth Factor / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D012313:RNA / Q000302:isolation & purification; D020917:Receptor, trkA / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014162:Transfection; D018909:src Homology Domains; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism*
D004791:Enzyme Inhibitors; D012313:RNA; D020932:Nerve Growth Factor; D011505:Protein-Tyrosine Kinases; D020917:Receptor, trkA; D019061:src-Family Kinases; D020928:Mitogen-Activated Protein Kinases