Syk

Spleen tyrosine kinase
File:PBB Protein SYK image.jpg PDB rendering based on 1a81.
Available structures PDB Ortholog search: Template:Homologene2PDBe PDBe, Template:Homologene2uniprot RCSB List of PDB id codes 1a81​, 1csy​, 1csz​, 1xba​, 1xbb​, 1xbc​
Identifiers
Symbols	SYK ;
External IDs	Template:OMIM5 Template:MGI HomoloGene: 2390
Gene ontology Molecular function Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Cellular component Template:GNF GO Template:GNF GO Template:GNF GO Biological process Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO
RNA expression pattern
File:PBB GE SYK 209269 s at tn.png
File:PBB GE SYK 207540 s at tn.png
More reference expression data
Orthologs
Template:GNF Ortholog box
Species	Human	Mouse
Entrez	n/a	n/a
Ensembl	n/a	n/a
UniProt	n/a	n/a
RefSeq (mRNA)	n/a	n/a
RefSeq (protein)	n/a	n/a
Location (UCSC)	n/a	n/a
PubMed search	n/a	n/a

Spleen tyrosine kinase, also known as SYK, is a human protein and gene.

SYK, along with Zap-70, is a member of the Syk family of tyrosine kinases. These non-receptor cytoplasmic tyrosine kinases share a characteristic dual SH2 domain separated by a linker domain.

While Syk and Zap-70 are primarily expressed in hematopoietic tissues, there is expression of Syk in a variety of tissues. Within B and T cells respectively, Syk and Zap-70 transmit signals from the B-Cell receptor and T-Cell receptor. Syk plays a similar role in transmitting signals from a variety of cell surface receptors including CD74, Fc Receptor, and integrins.

Abnormal function of Syk has been implicated in several instances of hematopoeitic malignancies including translocations involving Itk and Tel. Constitutive Syk activity can transform B cells. Several transforming viruses contain "Immunoreceptor Tyrosine Activation Motifs" (ITAMs) which lead to activation of Syk including Epstein Barr virus, bovine leukemia virus, and mouse mammary tumor virus.

The role of Syk in epithelial malignancies is controversial. Several authors have suggested that abnormal Syk function facilitates transformation in Nasopharyngeal carcinoma and head and neck cancer while other authors have suggested a tumor supressor role in breast and gastric cancer.

Further reading

• Turner M, Schweighoffer E, Colucci F; et al. (2000). "Tyrosine kinase SYK: essential functions for immunoreceptor signalling". Immunol. Today. 21 (3): 148–54. PMID 10689303.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Fruman DA, Satterthwaite AB, Witte ON (2000). "Xid-like phenotypes: a B cell signalosome takes shape". Immunity. 13 (1): 1–3. PMID 10933389.CS1 maint: Multiple names: authors list (link)
• Yanagi S, Inatome R, Takano T, Yamamura H (2001). "Syk expression and novel function in a wide variety of tissues". Biochem. Biophys. Res. Commun. 288 (3): 495–8. doi:10.1006/bbrc.2001.5788. PMID 11676469.CS1 maint: Multiple names: authors list (link)
• Tohyama Y, Yamamura H (2006). "Complement-mediated phagocytosis--the role of Syk". IUBMB Life. 58 (5–6): 304–8. doi:10.1080/15216540600746377. PMID 16754322.
• Schymeinsky J, Mócsai A, Walzog B (2007). "Neutrophil activation via beta2 integrins (CD11/CD18): molecular mechanisms and clinical implications". Thromb. Haemost. 98 (2): 262–73. PMID 17721605.CS1 maint: Multiple names: authors list (link)

External links

• Syk+kinase at the US National Library of Medicine Medical Subject Headings (MeSH)

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