Description
CSK is a cytoplasmic tyrosine kinase that has been shown to downregulate the tyrosine kinase activity of the c-src oncoprotein through tyrosine phosphorylation of the c-src carboxy terminus (1). Cell transformation by src oncoprotein is caused by several oncogenic mechanisms, which interfere with the carboxy terminal phosphorylation. The CSK could therefore potentially function as an anti-oncogene. CSK is ubiquitously expressed in human tissues as 2 mRNA species of 2.6 and 3.4 kb, although in some tissues and cell lines, only the larger mRNA is detected (2). A yeast 2-hybrid system has been used to identify proteins associated with CSK. The Src homology-3 (SH3) domain of CSK associates with a proline-rich region of PEP, a protein-tyrosine phosphatase expressed in hemopoietic cells (2). This association is highly specific and it is speculated that PEP may be an effector and/or regulator of CSK in T cells and other hemopoietic cells. An in situ hybridization has been used to map the CSK gene to chromosome 15q23-q25 (3).
Biomolecule/Target: N/A
Synonyms: CSK, C-src tyrosine kinase
Alternates names: CSK, C-src tyrosine kinase, Protein-tyrosine kinase CYL
Taglines: Phosphorylates human Src
NCBI Gene ID #: 1270
NCBI Gene Symbol: CNTF
Gene Source: N/A
Accession #: P26441
Recombinant: Yes
Source: Baculovirus (Sf9 insect cells)
Purity by SDS-PAGEs: 99%
Assay: SDS-PAGE
Purity: N/A
Assay #2: HPLC
Endotoxin Level: N/A
Activity (Specifications/test method): 425 nmol phosphate incorporated into Poly(Glu-Tyr) per minute per mg protein at 30°C for 15 minutes using a final concentration of 50 µM ATP (0.83 µCi/assay).
Biological activity: N/A
Results: N/A
Binding Capacity: N/A
Unit Definition: N/A
Molecular Weight: 78.0 kDa
Concentration: 5µg/50 µl
Appearance: Lyophilized powder
Physical form description: Lyophilized from sterile 20 mM Tris, 500 mM NaCl, 0.5 mM PMSF, pH 7.4, 5% trehalose and 5% mannitol.
Reconstitution Instructions: N/A
Amino acid sequence: N/A