Description

The Src family tyrosine kinase p56^Lck (Lck) is a non-receptor tyrosine kinase that plays a critical role in T cell selection and maturation within the thymus, and also in the function of mature T cells. Lck, which is constitutively bound to cytosolic domains of CD4 and CD8 surface receptors, plays an essential role in T cell receptor (TCR) signaling. Engagement of the TCR with peptide antigen-loaded MHC complexes results in the recruitment of CD4- and CD8-bound Lck to the TCR/CD3 signaling complex. Lck then transphosphorylates TCR-gamma chains and CD3 subunits, thereby activating the TCR/CD3 signaling pathway and leading to the recruitment and subsequent phosphorylation of Zap70 by Lck. Lck also plays an important role in interleukin-2 signaling that regulates the T cell proliferative response. Phosphorylation of Lck by CSK at tyrosine 505 negatively regulates the kinase, and is proposed to generate a closed, inactive conformation of the protein. Conversely, phosphorylation at tyrosine 394 in the activation loop of Lck greatly stimulates enzymatic activity. In many types of cancer, Lck is a proliferative and anti-apoptotic driver, and has been proposed as a target for therapeutic intervention.

Formulation

Recommended Usage

Each lot of this antibody is quality control tested by intracellular immunofluorescent staining with flow cytometric analysis. For flow cytometric staining, the suggested use of this reagent is 5 µL per million cells in 100 µL staining volume or 5 µL per 100 µL of whole blood.

References

1. Hastings WD, et al. 2009. Eur. J. Immunol. 39:2492. (Costim)
2. Jones RB, et al. 2008. J. Exp. Med. 205:2763. (Block)
3. Klibi J, et al 2009. Blood 113:1957. (FC, Block)