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Tec protein‐tyrosine kinase is an effector molecule of Lyn proteni‐tyroenie kinase
Author(s) -
Mano Hiroyuki,
Yamashita Yoshihiro,
Miyazato Akkra,
Miura Yasusada,
Ozawa Keiya
Publication year - 1996
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.10.5.8621063
Subject(s) - lyn , tec , proto oncogene tyrosine protein kinase src , tyrosine kinase , kinase , chemistry , effector , tyrosine , pleckstrin homology domain , bruton's tyrosine kinase , microbiology and biotechnology , biology , signal transduction , biochemistry , ionosphere , physics , astronomy
The Tec family is a recently emerging subfamily among nonreceptor type protein‐tyrosine kinases (PTKs) consisting of Tec, Txk, Btk, Bmx, and Itk/Tsk/Emt. They have a long amino‐terminal unique region containing a pleckstrin homology domain and a Tec‐homology domain. We could previously show that, through the Tec‐homology domain, Tec is bound to Lyn kinase both in vitro and in vivo. Because Tec is coexpressed with Lyn in many hematopoietic cell types, it has been intriguing to investigate the biological role of the Tec‐Lyn association. Here we demonstrate that Lyn can phospho‐rylate tyrosine residues of the Tec protein, and thereby activate Tec in 3T3 fibroblasts. However, coexpression of Tec has little effect on the phospho‐tyrosine‐contents of Lyn. By using the in vitro kinase assay and the yeast system, we could prove that the Tec protein is a direct substrate of the Lyn kinase both in vitro and in vivo. From this evidence we conclude that Tec acts downstream of Lyn in intracellular signaling pathways. This is a novel case where one PTK is phosphorylated and regulated by an‐other.—Mano, H., Yamashita, Y., Miyazato, A., Mi‐ura, Y., Ozawa, K. Tec protein‐tyrosine kinase is an effector molecule of Lyn protein‐tyrosine kinase. FASEB J. 10, 637‐642 (1996)