Grb10/GrbIR as an in vivo substrate of Tec tyrosine kinase.
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Mano H, Ohya K, Miyazato A, Yamashita Y, Ogawa W, Inazawa J, Ikeda U, Shimada K, Hatake K, Kasuga M, Ozawa K, Kajigaya S
Grb10/GrbIR as an in vivo substrate of Tec tyrosine kinase.
Genes Cells. 1998 Jul;3(7):431-41.
- PubMed ID
- 9753425 [ View in PubMed]
- Abstract
BACKGROUND: Tec is a member of the recently emerging subfamily among nonreceptor protein-tyrosine kinases (PTKs). Although many members of this family have been shown to be involved in a wide range of cytokine-mediated signalling systems, the molecular mechanism by which they exert in vivo effects remains obscure. To gain insights into the downstream pathways of Tec, we here looked for Tec-interacting proteins (TIPs) by using the yeast two-hybrid screening. RESULTS: One of TIPs turned out to be Grb10/GrbIR, which carries one pleckstrin homology domain and one Src homology 2 domain. Grb10/GrbIR was known to bind receptor PTKs in a ligand-dependent fashion, but not to be phosphorylated on tyrosine residues. In a transient expression system in human kidney 293 cells, however, Grb10/GrbIR becomes profoundly tyrosine-phosphorylated by Tec, but not by Syk, Jak2 or insulin receptor. We also reveal that expression of Grb10/GrbIR suppresses the cytokine-driven and Tec-driven activation of the c-fos promoter. CONCLUSION: Our results indicate a novel role of Grb10/GrbIR as an effector molecule to a subset of nonreceptor PTKs.