ZAP 70 (TCR Zeta Associated Protein kinase 70kD)

Engagement of the T-cell receptor (TCR) by antigen activates a biochemical cascade that involves both protein tyrosine kinases (PTKs) and tyrosine phosphatases and culminates in cytokine release, cellular proliferation, and cellular differentiation. Although the multi-chain TCR does not possess intrinsic kinase activity, at least three PTKs have been implicated in proximal TCR signaling events including: Fyn, Lck, and ZAP70. Fyn and Lck are members of the Src-family of tyrosine kinases, whereas ZAP70 is a member of the Syk family. ZAP70 is a 70kD PTK and can be functionally divided into three domains: two SH2 domains, and a C-terminal PTK domain. As described, ZAP70 is structurally homologous to the Syk PTK. However, ZAP70 and Syk have distinct tissue distributions with ZAP70 expressed exclusively in T-cells and natural killer cells, and Syk expressed predominantly in B cells, thymocytes, and myleoid cells. Although these two PTKs have different tissue distributions, both play essential roles in the signal transduction pathways of various hematopoetic antigen receptors. In response to engagement of the TCR, ZAP70 undergoes tyrosine phosphorylation and associates with the tyrosine phosphorylated TCRz and CD3 subunits. Tyrosine phosphorylation of TCRz and ZAP70, and their subsequent association is dependent upon the Lck and Fyn PTKs. Association of ZAP70 with the TCR requires receptor stimulation and is mediated by two phosphorylated tyrosine residues present in a 17 amino acid motif referred to as ITAM for intracellular tyrosine activation motif. This motif is present in the TCRz chain, as well as In the CD3-e,-g,-d subunits. The essential role for ZAP70 in T-cell development and activation has been perhaps best demonstrated by studies showing a loss of T cell signaling when the recruitment of ZAP70 to the activated TCR is disrupted, and by the identification of patients with severe combined immunodeficiency who carry a mutation of ZAP70 which results in the production of a kinase defective protein. Recent evidence has suggested that ZAP70 should be considered as an effective biomarker in Chronic Lymphocytic Leukemia (CLL). \nApplications: \nSuitable for use in ELISA, Western Blot and Immunoprecipitation. Other applications not tested.\nRecommended Dilution:\nELISA: 0.1-1.0ug/ml \nWestern Blot: 1ug/ml\nImmunoprecipitation: 5ug \nOptimal dilutions to be determined by the researcher.\n\nPositive Control: Human Jurkat cells.\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. For long-term storage, store at -20 degrees C. Aliquots are stable for at least 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

Z0300-03

Size

50ug

Applications

ELISA, IP, WB

Hosts

Mouse

Reactivities

Hum, Mouse

Form

Supplied as a liquid in PBS, pH 7.4, 0.05% sodium azide, before the addition of glycerol to 40%.

P Type

Mab

Purity

Purified by immunoaffinity chromatography.

Isotype

IgG1,k

References

1. Chan, A.C., et al., (1994) Ann. Rev. Immunol. 12: 555-592. 2. Irving, B.A. and Weiss, A. (1991) Cell 64: 891-901. 3. Chan, A.C., et al., (1992) Cell 71: 649-662. 4. Chan, A.C., et al., (1994) J. Immunol. 152: 4,758-4,766. 5. Arapaia, E., et al., (1994) Cell 76: 947-958. 6. Elder, M.E., et al., (1994) Science 264: 1,596-1,599. 7. Chan, A.C., et al., (1994) Science 364: 1,599-1,601. 8. Wange, R.L., et al., (1995) J. Biol. Chem. 270: 944-948.

Additional Info

Recognizes human ZAP-70 protein tyrosine kinase (PTK) and does not exhibit any crossreactivity with the related Syk PTK \nSpecies Crossreactivity: mouse.