Reengineering the Signaling Properties of a Src Family Kinase

Department of Physiology and Biophysics, School of Medicine, Stony Brook University, Stony Brook, New York 11794-8661, USA.
Biochemistry (Impact Factor: 3.02). 10/2009; 48(46):10956-62. DOI: 10.1021/bi900978f
Source: PubMed


Src family kinases (SFKs) are modular signaling proteins possessing SH3, SH2, and tyrosine kinase domains. The SH3 and SH2 domains of SFKs have dual roles: they regulate the activity of the kinases, and they also target SFKs to their cellular substrates. We generated a series of novel SFKs by replacing the SH2 and SH3 domains of Hck with the syntrophin PDZ domain. In some constructs, the negative regulatory tyrosine in the C-terminal tail was also replaced with a PDZ ligand sequence. When expressed in mammalian cells, the substrate specificity of the PDZ-kinases was directed to a different group of proteins than wild-type Hck. The PDZ-kinases phosphorylate neuronal nitric oxide synthase (nNOS), a known binding partner of the syntrophin PDZ domain. We also introduced a PDZ ligand at the C-terminus of the adaptor protein Cas. PDZ-Hck kinases phosphorylate the engineered Cas protein in Cas(-/-) cells and restore the migration defect of these cells. A PDZ-kinase was also functional in rewiring MAPK signaling via an engineered ErbB2 construct containing a PDZ ligand sequence. Several of the PDZ-kinases show autoregulatory properties similar to natural SFKs. Thus, the PDZ-ligand interaction is able to functionally replace the normal SH2-pY527 interaction that regulates SFKs. Our data highlight the modularity and evolvability of signaling proteins.

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    • "Different systems have been used to study SFK substrates and signal transduction pathways. The hemopoietic cell Src kinase (Hck) was reengineered by substituting the SH2 and SH3 domains with a PDZ domain to alter the kinase's substrate specificity [40]. In another study, a temperature-sensitive vSrc mutant was found to increase tyrosine phosphorylation of cortactin [41]. "
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