Src homology 2 domains of protein tyrosine phosphatase are phosphorylated by insulin receptor kinase and bind to the COOH-terminus of insulin receptors in vitro.
To clarify the role of protein tyrosine phosphatases(PTPase) containing Src homology 2 (SH2) regions on insulin signaling, we investigated the interactions between SH2 regions of PTPase and insulin receptors. We made a pair of SH2 domains of PTP1C and SH-PTP2 fusion proteins coupled to glutathione-S-transferase (GST) using pGEX-3X expression vector. After incubating with insulin, insulin receptors were incubated with SH2 proteins in the presence of 100 mu ATP at 4 degrees C for 3 hr, and then immunoprecipitated and analyzed by SDS-PAGE. We found that SH2 domains of SH-PTP2 were phosphorylated, but not those of PTP1C by insulin receptor kinase and the SH2 domains of SH-PTP2, but not those of PTP1C, directly bound to the phosphorylated COOH-terminus of insulin receptors in vitro.
Third Department of Medicine, Shiga University of Medical Science, Japan.
H
H
Maegawa
S
S
Ugi
O
O
Ishibashi
R
R
Tachikawa-Ide
N
N
Takahara
Y
Y
Tanaka
Y
Y
Takagi
R
R
Kikkawa
Y
Y
Shigeta
A
A
Kashiwagi
D000595:Amino Acid Sequence; D001665:Binding Sites; D002460:Cell Line; D003001:Cloning, Molecular; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011972:Receptor, Insulin / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013379:Substrate Specificity
D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin; D017027:Protein Tyrosine Phosphatases