Journal of Cell Science 115, e1502-e1502 (2002)
© 2002 The Company of Biologists Limited
Tek kinases calcium and beyond
Tek family kinases, such as Btk and Itk, are non-receptor tyrosine kinases
related to the Src family. Initially shown to be important in immune cells for
Ca2+ mobilization during antigen receptor signalling, Tek kinases
function downstream of cell-surface receptors from Fc receptors to integrins.
In a Commentary on p. 3039,
Pamela Schwartzberg and co-workers review our understanding of the roles of
these kinases in signalling. Tek kinases possess the SH1, SH2 and SH3 domains
characteristic of Src kinases but contain additional, pleckstrin-homology (PH)
and proline-rich (PR) domains. The PH domain regulates membrane targeting by
binding to phospholipids such as the PI 3-kinase product
PtdIns(3,4,5)P3. The PR domain appears to engage in inter-
and intra-molecular PR-SH3 interactions, disruption of which could activate
the kinase. Once activated, Tek kinases regulate Ca2+ signalling by
phosphorylating phospholipase C
. However, they also regulate signalling
by MAP kinases and STATs, as well as by actin reorganization. Indeed
interactions between Tek kinases and actin regulators such as WASP could be
critical for formation of the immunological synapse required for sustained
signalling by T-cell receptors.
Related articles in JCS:
- Beyond calcium: new signaling pathways for Tec family kinases
- Aya Takesono, Lisa D. Finkelstein, and Pamela L. Schwartzberg
JCS 2002 115: 3039-3048.
[Abstract]
[Full Text]