Lck is a lymphoid-specific cytosolic protein tyrosine kinase (PTK), which is essential for T-cell development and function. It is constitutively associated with the cytoplasmic portions of the CD4 and CD8 surface receptors and plays a key role in T-cell antigen receptor (TCR)-linked signal transduction pathways. Association of the TCR with a peptide antigen-bound MHC complex facilitates the interaction of CD4 and CD8 with MHC class II and class I molecules, respectively, and thereby recruits the associated Lck to the vicinity of the TCR/CD3 complex. Lck then phosphorylates tyrosine residues within the immunoreceptor tyrosine-based activation motifs (ITAMs) in the cytoplasmic tails of the TCR-chains and CD3 subunits. The phospho-ITAMs serve as docking sites for Src homology domain 2 (SH2)-containing molecules, predominantly ZAP-70 and Syk. Only then can ZAP-70 undergo tyrosine phosphorylation, become enzymatically active and further phosphorylate downstream effector molecules. In addition, Lck contributes to signaling by other receptor molecules. Lck is expressed at all stages of thymocyte development and is required for the regulation of maturation events that are governed by both pre-TCR and mature TCR.
Positive Control: Jurkat
Applications:
Suitable for use in Western Blot. Other applications not tested.
Recommended Dilution:
Optimal dilutions to be determined by the researcher.
Storage and Stability:
May be stored at 4 degrees C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot 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.