Src-family and Syk kinases in activating and inhibitory pathways in innate immune cells: signaling cross talk.
The response of innate immune cells to growth factors, immune complexes, extracellular matrix proteins, cytokines, pathogens, cellular damage, and many other stimuli is regulated by a complex net of intracellular signal transduction pathways. The majority of these pathways are either initiated or modulated by Src-family or Syk tyrosine kinases present in innate cells. The Src-family kinases modulate the broadest range of signaling responses, including regulating immunoreceptors, C-type lectins, integrins, G-protein-coupled receptors, and many others. Src-family kinases also modulate the activity of other kinases, including the Tec-family members as well as FAK and Pyk2. Syk kinase is required for initiation of signaling involving receptors that utilize immunoreceptor tyrosine activation (ITAM) domains. This article reviews the major activating and inhibitory signaling pathways regulated by these cytoplasmic tyrosine kinases, illuminating the many examples of signaling cross talk between pathways.
Department of Laboratory Medicine, University of California, San Francisco, 94143, USA. clifford.lowell@ucsf.edu
Clifford A
CA
Lowell
D053468:CARD Signaling Adaptor Proteins / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008954:Models, Biological; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D020239:Receptor Cross-Talk / Q000276:immunology*; D011971:Receptors, Immunologic / Q000378:metabolism*; D015398:Signal Transduction / Q000276:immunology*; D000072377:Syk Kinase; D019061:src-Family Kinases / Q000378:metabolism*
D053468:CARD Signaling Adaptor Proteins; C505855:CARD9 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D011971:Receptors, Immunologic; D011505:Protein-Tyrosine Kinases; C000606896:SYK protein, human; D000072377:Syk Kinase; D019061:src-Family Kinases