TY - JOUR
T1 - Tyrosine Kinase Activity of the ret Proto-oncogene Products inVitro
AU - Miyazaki, K.
AU - Asai, N.
AU - Iwashita, T.
AU - Taniguchi, M.
AU - Isomura, T.
AU - Funahashi, H.
AU - Takagi, H.
AU - Matsuyama, M.
AU - Takahashi, M.
PY - 1993/6/15
Y1 - 1993/6/15
N2 - We investigated tyrosine kinase activity of the ret proto-oncogene products (proto-Ret proteins), using a cell lysate of NB-39-nu neuroblastoma cells. The 150 kDa and 170 kDa proto-Ret proteins immunoprecipitated with antibodies against their carboxy-terminal 20 amino acids were shown to be phosphorylated predominantly on tyrosine residues in immunocomplex kinase assay. The level of tyrosine phosphorylation of the 150 kDa proto-Ret protein was approximately 10-fold higher than that of the 170 kDa proto-Ret protein, although both proteins were expressed at similar levels in neuroblastoma cells. This result was confirmed by using a lysate of SK-N-MC human primitive neuroectodermal tumor cells transfected with the ret proto-oncogene. The kinase activity of proto-Ret proteins was significantly inhibited by antibodies against their kinase domain, indicating that these antibodies recognize crucial epitopes for the enzymatic activity. On the other hand, the proto-Ret proteins were not phosphorylated in vivo in NB-39-nu cells and SK-N-MC transfectants.
AB - We investigated tyrosine kinase activity of the ret proto-oncogene products (proto-Ret proteins), using a cell lysate of NB-39-nu neuroblastoma cells. The 150 kDa and 170 kDa proto-Ret proteins immunoprecipitated with antibodies against their carboxy-terminal 20 amino acids were shown to be phosphorylated predominantly on tyrosine residues in immunocomplex kinase assay. The level of tyrosine phosphorylation of the 150 kDa proto-Ret protein was approximately 10-fold higher than that of the 170 kDa proto-Ret protein, although both proteins were expressed at similar levels in neuroblastoma cells. This result was confirmed by using a lysate of SK-N-MC human primitive neuroectodermal tumor cells transfected with the ret proto-oncogene. The kinase activity of proto-Ret proteins was significantly inhibited by antibodies against their kinase domain, indicating that these antibodies recognize crucial epitopes for the enzymatic activity. On the other hand, the proto-Ret proteins were not phosphorylated in vivo in NB-39-nu cells and SK-N-MC transfectants.
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U2 - 10.1006/bbrc.1993.1661
DO - 10.1006/bbrc.1993.1661
M3 - Article
C2 - 7685595
AN - SCOPUS:0027177525
SN - 0006-291X
VL - 193
SP - 565
EP - 570
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -