SYK is a non-receptor tyrosine kinase that mediates signal transduction downstream of various transmembrane receptors, including classical immunoreceptors like the B-cell receptor (BCR). It regulates key processes such as innate and adaptive immunity, cell adhesion, osteoclast maturation, platelet activation, and vascular development.
SYK assembles into signaling complexes at the plasma membrane via its SH2 domains binding to receptor tyrosine-phosphorylated ITAM domains or indirectly through adapter proteins with ITAM or hemITAM domains. ITAM phosphorylation is typically mediated by SRC kinases upon receptor engagement. SYK also phosphorylates downstream effectors, including DEPTOR, VAV1, PLCG1, LCP2, and BLNK. Initially identified as essential in BCR signaling, SYK facilitates B-cell maturation, phosphorylates BLNK to link the activated BCR to downstream signaling, and regulates the PKC and BTK pathways
Beyond BCR, SYK contributes to T-cell receptor signaling and innate immune responses to pathogens. It is activated by CLEC7A upon fungal protein stimulation, inducing ROS production, inflammasome activation, and NF-kappa-B-mediated transcription of chemokines and cytokines. SYK also regulates neutrophil degranulation, phagocytosis, and MAPK signaling. It activates dendritic cells, mast cells, and basophils in response to stimuli.
SYK mediates integrin-dependent adhesion in neutrophils and macrophages, leukocyte recruitment, and vascular development, regulating blood-lymphatic separation. It plays roles in osteoclast function and platelet activation, facilitating PLCG2 phosphorylation and adhesion via fibrinogen-engaged ITGB3. Additionally, SYK enhances CXCL8/IL-8 production, supporting intestinal immunity.
| Product Name | Recombinant Human Syk Protein |
| Accession | P43405 |
| Host Species | Human |
| Gene | SYK |
| Source | Sf9 (Baculovirus infected) |
